Global Climates

Chapters 10 and 11 (4CE) (Chapter 10 (3CE))

**There is a video version of this lecture here:

**The exam is based on the content in these notes, so please print them off to study from.


  • Climate refers to long-term weather patterns (“weather” is what is happening right now, this moment)
  • Climatology is the study of climate and its variability over time and space
  • Climatic regions are places with broadly similar climatic conditions.

You need to read the introductory sections in Chapter 10, up to and including the introduction to the “Köppen-Geiger Climate Classification System,” 4CE pp. 275-281 / 3CE pp. 262-273.

I. The Components of Climate

See Geosystems in Action 10, “Earth’s Climate System” (p. 278-9).

Climates are classified on the topics we have already discussed in the course:

 1. Insolation

  • The amount of incoming solar radiation (insolation) a location receives will affect its climate.  This is directly linked to latitude (Figure 2.9, (2.10; 3CE) Daily insolation received at the top of the atmosphere”)

2. Energy Balance

  • The imbalance, created by energy surpluses at the equator and energy deficits at the poles, causes global circulation patterns of winds and ocean currents.

3. Temperature

  • In Chapter 5 we discussed global temperatures.  Temperatures are directly linked to insolation (latitude), altitude, cloud cover, and land-water heating differences.

4. Air Pressure

  • Winds flow form High to Low Pressure.  The ITCZ, a region of low pressure, is wet.  The subtropics, regions of high pressure, are hot and dry.  Other variables including ocean currents, and oscillations (El Nino, La Nina) affect these patterns.

5.  Air Masses

  • As air masses migrate, they bring their temperature and moisture conditions to new locations.

6. Precipitation

  • The amount and type of precipitation in a region will affect its climate.

Obviously these six factors do not operate independently!

  • Temperature is directly linked to insolation.
  • Precipitation is directly lined to global circulation patterns, land/water location, and air masses.
  • Air masses are directly related to a location’s proximity to land/water.

For instance, global circulation patterns create regions like the sub-tropical high pressure regions (around the tropics).  These circulation patterns cause dry, sunny, warm conditions.  These conditions, in turn, create a hot, arid climate.

A climograph is used to show the climate for a particular location.  It includes information like:

  • A graph of monthly temperatures
  • A graph of monthly precipitation
  • Location coordinates
  • Average annual temperature
  • Average annual precipitation
  • Total annual precipitation
  • Annual temperature range
  • Annual hours of sunshine
  • Elevation
  • Population

As we go through various types of climates, you will see representative climographs for each climate region.  No, you don’t have to memorize these.  Do figure out how to READ them.  Know the TYPE of information presented.  In your lab you will have the opportunity to work with this information a bit.

II. Classifying Climate

Places around the world are most often grouped into climatic regions using the Köppen-Geiger Classification System.  This system uses statistical data to group places with similar climatic conditions into larger categories.  In your text, they have modified this system somewhat.  To avoid confusion, we will use the system used in your text.

There are six basic climate categories:

  1. Tropical climates – tropical latitudes, no winter
  2. Mesothermal climates – mid-latitudes, mild winter
  3. Microthermal climates – mid- to high- latitudes, cold winters
  4. Polar climates – high latitudes and polar regions
  5. Highland climates – high alpine elevations
  6. Dry climates – areas with a permanent moisture deficit (deserts)
  1. Tropical regions (warm, equatorial regions)

Tropical climates, between about 20 degrees N and S are characterized by consistent day-length and insolation, warm temperatures, lots of warm oceans for evaporation, and either constant or seasonal influences from the ITCZ.  Remember the ITCZ moves with the sun north and south of the Equator.  At the ITCZ, trade winds converge, a low pressure belt develops, air rises, and there is much precipitation. 

a. Tropical Rain Forest Climates are always moist and warm.  These areas are influenced by the ITCZ low pressure belt all year.  Convectional precipitation happens virtually every day, resulting in lush forest growth (rain forests).  Because the leaf canopy is so dense, little light diffuses to the forest floor, meaning there is little vegetation on the forest floor (except along river banks, where light can reach the ground).

b. Tropical Monsoon Climates receive rainfall from the ITCZ 6-12 months of the year, but also have a dry season, when the sun (and hte ITCZ) is over the other hemisphere.  These are coastal areas, receiving much monsoon precipitation.  These areas ofen have forest and grasslands, depnding on how much precipitation is received.

c. Tropical Savanna Climates receive intense rain from the ITCZ lows less than 6 months of the year.  When the sun (and the ITCZ) are overhead, they receive much rainfall.  When the sun (and ITCZ) are over the other hemisphere, they have a prolonged dry season.  These are often grassland areas.

2. Mesothermal climates – mid-latitudes, mild winter

North and south of the tropics are “mesothermal” or “middle temperature” regions.  Because these regions are in mid-latitudes, they have stronger seasonality – warm/hot summers and cool (but not cold) winters.  Since they are in the westerly wind belt and since they are in regions where several air masses can interact, their weather is much less predictable than in tropical regions.

a. Humid-subtropical hot-summer climates (think of the SE USA – Louisiana, Florida, Georgia).  Fairly moist all year long, with hot, humid summers and not-so-hot (but certainly not cold) winters.  These areas are susceptible to hurricanes, generated by intense summer heating of ocean waters.

b. Humid-subtropical winter-dry climates (not widespread in North America, but common in China and India).  Hot summer but dry winters (for example, South Asian monsoon regions). 

c. Marine west coast climates (west coast of North Amerca, NW Europe, New Zealand, SE Australia).  Mild winters.  Cool summers.  These regions are unusually mild for their latitudes due to the moderating effect of oceans and ocean currents (remember our continentailty discussion).

d. Mediterranean dry-summer climates (Southern California and the Mediterranean Basin).  Warm dry summers, but often wet winters.

3. Microthermal climates (mid- to high- latitudes, cold winters)

Further toward the poles from the mesothermal climates, microthermal (“little temperature”) regions have cool/warm summers, but COLD winters.  These are areas which, in winter, receive less insolation.  And also do no receive the moderating effect of stored energy in the oceans, warm ocean currents, and maritime air masses.

a. Humid continental hot-summer climates (think of places like the US Midwest through to New York). These areas have precipitation year-round; they can be very hot and humid in the summer and cold and snowy in the winter.  They are often mixed forest regions.

b. Humid continental mild-summer climates (think of the Great Lakes region, St. Lawrence Valley, Maritime Provinces).  Like the hot-summer climates, these regions have precipitation year-round, but a are less hot in the summer and more cold and snowy in the winter.  They are often mixed forest regions.

c. Subarctic climates (think of the northern halves of the Alberta, Saskatchewan, Manitoba, Ontario, Quebec, and all of Newfoundland – and most of Russia/Siberia – up to the tree line).  Because these regions are closer to the poles, they have stronger seasonality – long summer days, short winter days and COLD winters.  These are boreal forest/taiga regions – fir, spruce, and larch.  Inland areas can have very cold and dry winters.  Coastal areas, like Newfoundland, can be cold AND moist.

4/5.  Polar and Highland climates

Polar climates have no true summer – temperatures rarely rise above 10 degrees C.  Trees cannot survive in these latitudes.  Highland climates can occur at any latitude where mountains are high enough that climatic conditions are similar to that at the poles. 

a. Tundra climates (think of the Arctic, north of the tree line, and high alpine areas above the tree line).  “Tundra” refers to the characteristic vegetation in these regions where plant growth is restricted by cold temperatures and a short growing season.  They are seasonally covered by ice and snow.  In spring, when snow melts, arctic and alpine flowers bloom.  Permafrost (which we look at in the other course) is common in these regions (Chapter 17).

b. Ice-cap/Ice-sheet climates (think of Greenland and Antarctica).  These regions are continuously covered in ice and snow.  They are dominated by cold, dry air masses and temperatures that rarely go above freezing, even in summer.  FYI, Antarctica is actually a cold desert, receiving less than 10 mm of precipitation each year.  Imagine how long it has taken the ice – several kms thick – to accumulate.

6. Dry climates

Dry climates are classified both as regions with VERY little moisture and high temperatures.  They tend to coincide with sub tropical high pressure belts, are located in the leeward (rain shadow) side of major mountain ranges, and continental interiors far from maritime influences.

a. Deserts (think of the Sahara Desert, Death Valley California, Arizona, Nevada, the Middle East, and central Australia).  Some deserts are “hot” deserts (average temperature always above 18 degrees C), some are “cold” deserts (with a winter cold season).  Deserts are VERY dry with a huge soil moisture deficit.  They capable of supporting little or no vegetation. 

b. Steppes (think of the Great Plains/grasslands of central North America, including southern Alberta and Saskatchewan, AND grasslands in Africa, Ukraine and Central Asia).  Steppes are too dry to support trees, but are more moist than deserts – they can support grasslands.

III. Climate Change (4CE Chapter 11, 3CE Chapter 10, pp. 294-304)

NOTE:  we will use the term “climate change” rather than “global warming.”  This is a more comprehensive — and accurate term.  Global climates are changing … warming is just one indicator of this in many parts of the world.  The bigger issue is CHANGE.  While climates may be getting warmer in some areas, the bigger issues may be more frequent and more violent storms, less or more precipitation (annually or seasonally), greater (or less) wind, etc.  For instance, extended hot-dry periods during the summers on the west coast and exceptionally nasty winter storms on the east coast exemplify climate change – in the latter case not necessarily warming!

“Climate change” encompasses global warming, but refers to the broader range of changes that are happening to our planet. These include rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times. These are all consequences of the warming, which is caused mainly by people burning fossil fuels and putting out heat-trapping gases into the air. The terms “global warming” and “climate change” are sometimes used interchangeably, but strictly they refer to slightly different things.

Good online readable introduction to all topics related to climate change include:

With all the recent rhetoric by our political leaders and others  this section should be very interesting to you!

The U.N. World Meteorological Organization’s Intergovernmental Panel on Climate Change is the world’s premier peer-reviewed scientific authority on climate change, with several thousand atmospheric scientists involved.  This is the best source of all scientific information on climate change.

The IPCC Climate Change: Global Risks, Challenges and Decisions highlighted that:

  • Scientific observations indicate that climate change is happening as fast as or faster than the highest estimates previously anticipated,  This is having dramatic consequences for average surface temperatures, glacier and sea-ice retreats, sea water levels, and local and regional weather.
  • Social Disruption and equity dimensions need to be addressed:  All societies are impacted by the consequences of climate change.  However some of the poorest nations and regions (e.g. Sub-Saharan Africa, southeast Asia and Arctic regions are most affected and are least able to cope.
  • Inaction is inexcusable.  The scientific case is solid; climates are changing.  Technological, economic, and management resources exist to substantially mitigate the process and effects of climate change … but the political will is often lacking.
  • Meeting the challenging requires grassroots and political leadership to have a new vision and will power.  There could be substantial longterm economic, employment and health benefits from a “decarbonized” society, but the desire has to be there to make it happen.

The UN reports are considered conservative in their scientific assessments.

The debate about climate change among scientists — if it ever really existed — has long been over.  The (very few, about 3%) nay-sayers rarely deny change is occurring, but may debate the relative effect of human activity.  It is true that climate has fluctuated naturally over the Earth’s history.  However the current pace of change and extent of change is unprecedented.  It is also directly correlated with increases in human population and industrial activity (particularly CO2 production).  This, in turn, traps long-wave radiation emitted by the Earth, amplifying the Earth’s natural greenhouse effect.

The political debate — among politicians — is far from over!

The Earth does naturally produce some CO2, through plant respiration, microbial respiration and decomposition, and respiration and decomposition in oceans.  This has been relatively constant over past millennia.  Since the mid-19th Century, growing human populations and increasing industrial activity have resulted in dramatic increases in CO2 emissions and atmospheric CO2 concentrations (see Figure 11.2 “Carbon dioxide concentrations …” p. 309 – notice the major increase since the Industrial Revolution). 

  • This has primarily come from the increased burning of fossil fuels (coal, oil, natural gas). See Geosystems in Action 11, “The Global Carbon Budget,” 11.2, p.322.
  • Additional anthropogenic (human-caused) carbon emissions come from deforestation.  See Geosystems in Action 11, “The Global Carbon Budget,” 11.3, p.323.
  • Carbon emissions have also come from arctic permafrost thaw, primarily caused by global heating caused by rising CO2, caused by fossil fuel burning and deforestation.  See Geosystems in Action 11, “The Global Carbon Budget,” 11.4, p.323.

Rates of CO2 production are directly related to rates of population growth (compare Figures 11.3 “Human population growth” and 11.5 “The Keeling Curve…”).  The challenge of these graphs is that neither – not global population growth or global CO2 production – appear to be slowing down significantly.  This, of course, raises issues of sustainability.

    A Brief History of Climate (Deciphering Past Climates)

Earth’s climate has always changed naturally (and very slowly) over time.  The science of studying past climates is called paleoclimatology.  The text goes into methods for long-term and short-term climate reconstruction and histories in great detail (4CE, pp. 310-318) – skim this, but you do not need to know it for the exam.  It may give you some help in understanding how scientists assess climate is actually changing today.  For those who may wish to argue that there is no “evidence” for climate change, this section provides essential background reading.

    Mechanisms of Natural Climate Fluctuation (4CE pp. 319-320)

Climate does change (very very slowly) due to natural processes:

  1. Solar variability – the sun’s output of energy toward earth changes over time.  Overall it is increasing.  It also varies on an approximately 11-year cycle related to sunspot activity (it is greatest when there are the most amount of sunspots}.  There are also approximate 70 year cycles of reduced sunspot activity (in general, less sunspot activity has resulted in a time of global cooling).  Actual observed results of global temperatures suggest that these historic trends are no longer holding true.  2005-2010, a time of  low sunspot activity SHOULD have been a cool period, but instead were very warm, suggesting other effects are shaping climate (see NASA Earth’s Energy Budget Remained Out of Balance Despite Unusually Low Solar Activity)
  1. Earth’s orbital cycles
  • The Earth’s orbit is not a perfect circle, but an ellipse, meaning at times the Earth is closer to the sun and at times it is further away.
  • Earth’s axis “wobbles” meaning that at times one hemisphere is more tilted toward the sun than the other.  The tilt of the Earth’s axis varies from 21.5 – 24.5 degrees.  Currently it is 23.5 degrees.

All of these, of course, affect the insolation received at the top of the atmosphere and at the Earth’s surface and thus global temperatures. 

  1. Continental positions and topography – long-term changes in the relative amount/shape of land and oceans can affect climate (see text).  These affect temperatures over periods of millions/billions of years, certainly not on an annual basis.
  1. Atmospheric gases and aerosols – naturally occurring changes in the composition of the atmosphere can affect climate.  For instance volcanic eruptions tend to produce much atmospheric dust, blocking incoming solar energy, which can lead to global cooling.  Carbon dioxide (CO2), cause by burning of (presently or formerly) living organisms – e.g. forest fires burning large expanses of trees – has the net effect of raising global temperatures.  Increased water vapour in the atmosphere also increases global temperatures.
Causes of Present Climate Change

The important “Greenhouse Gases” are (4CE, pp. 328-323)

  • Carbon Dioxide (CO2) – present levels are the higher than at any point in the past 800,000 years. Concentrations are directly correlated with fossil fuel burning (wood, coal, gas, oil) associated with the Industrial Revolution, deforestation, and global population growth.  Given the extent of human fossil fuel burning, however, we would expect even higher levels of atmospheric CO2 than we, in fact, observe.  One important counter-measure is the oceans.  Oceans take up CO2 as it is dissolved in the water and through photosynthesis in phytoplankton, microscopic marine organisms.  When dissolved by seawater, CO2 forms carbonic acid, which leads to acidification in the oceans.  This has serious consequences for marine ecosystems, including coral environments. 
  • Methane – Levels of methane – considered the second most important greenhouse gas – are actually rising much faster than levels of CO2.  And methane is 25 times more effective at trapping atmospheric heat than CO2.   Livestock production, mining, oil and gas extraction (all related to human activity) are the main contributors.  Methane levels have also risen from the acceleration of thawing of the Northern permafrost and increased emissions from tropical wetlands, also related to human induced climate changes.
  • Nitrous oxide – from human industrial activity, used of fertilizers, and biomass and fossil fuel burning.  Nitrous oxide concentration in the atmosphere is now 20% higher than in the pre-industrial era.  
  • Halogenated gases – chlorofluorocarbons and fluorinated gases used in refrigerants and other human activities.  Chlorofluorocarbons (CFCs) and hydrofluorochlorocarbons (HCFCs) are dramatically increasing in the atmosphere – and are potent greenhouse gases .(BBC News – Climate concerns as ‘ozone-friendly’ HFCs use grows).  HFCs are much more potent global warming agents per molecule than carbon dioxide.  See Greenhouse Gases (Carbon Brief)

Don’t worry about the section on “Sources of radiative forcing” (p.331-332)

   Evidence of Present Climate Change

1.Temperature – The global temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time.  Earth’s atmospheric temperatures have risen since the 1880’s.  Figure 11.17, “Global land-ocean temperature trends …” (p.326) demonstrates this clearly.  The 19 warmest years on record, globally, have all occurred within the past two decades.  Overall, the past three decades have been the warmest decades in recorded history.  See the Instrumental Temperature Record.

Specifically looking at Canada, Environment Canada’s “Temperature Change in Canada,” notes that:

  • In Canada, the national average temperature for the year 2020 was 1.1 degree Celsius (°C) above the 1961 to 1990 reference value.  Eight of the 10 warmest years have occurred during the last 15 years, averaging 3.0°C above the 1961–1990 reference value.
  • From 1948 to 2020, there is a trend in annual average temperature departures, showing 1.8°C of warming over that period
  • Annual average temperatures were consistently above or equal to the reference value from 1993 onward
  • The annual average temperature in Canada has increased at roughly twice the global mean rate. Patterns are different across regions of the country. Temperatures have increased more in northern Canada than in southern Canada. Annual mean temperature over northern Canada increased by roughly 3 times the global mean warming rate.  Warming is greatest over land and at high latitudes, with some models predicting rises of 10°C in the next 100 years in the Arctic.  This has dramatic consequences for permafrost, ecosystems, structural engineering, and transportation (e.g. ice highways)
  • Temperatures are rising even faster than elsewhere in mountainous areas. When snow and ice recedes or even disappears from mountains, the bare soil beneath can warm unimpeded. A recent study found that mountainous areas above 2,000 meters (6,500ft) are warming about 75% faster than places at lower elevations.
  • See The Canadian Atlas Online – Climate Change

As we have seen in previous chapters, periods of extended heating and drought are becoming more intense globally (for instance in the SW USA, Australia, and North Africa). 

Ocean temperatures are also rising.  Sea surface temperature have increased since the 1880’s  and continues to rise.  From 1901 through 2020, temperature rose at an average rate of 0.07°C per decade.  This affects sea-level rise and marine ecosystems.  For up to the minute details see the EPA’s Climate Change Indicators: Sea Surface Temperature.


The issue is not that temperature change is happening.  The real challenge is coming to terms with the changes.

2. Ice Melt

Heating of Earth’s atmosphere and oceans is causing land ice and sea ice to melt.

a. Glacial Ice – Land ice occurs as glaciers, ice sheets, ice caps, ice fields, and frozen ground (permaforst).  Glacial ice is frozen fresh water.  As temperatures increase, glaciers are losing mass and shrinking in size globally.  Earth’s two largest ice sheets, in Greenland and Antarctica, are losing mass.  Permafrost is also thawing at accelerating rates.  This has all sorts of ecological and even economic implications.

See Figure 11.19, “Athabasca Glacier …” p.327.

Permafrost, perennially frozen ground, is thawing in the Arctic at accelerating rates.   Deposits of frozen methane, a potent greenhouse gas, and carbon dioxide lie beneath permafrost in Arctic regions. About a quarter of the Northern hemisphere is covered by permafrost. As the environment warms and the permafrost thaws, these deposits can be released into the atmosphere and present a risk of enhanced warming.

b. Sea Ice – Sea ice is frozen sea water forming over the ocean.  Sea ice is declining at 13% per decade, which has major environmental implications.  Sea ice is expected to decrease, with some projections predicting late-summer Arctic sea ice to disappear entirely by 2030.  Current sea ice levels are the lowest in several thousand years.

See Figure 11.20 “Recent changes in annual Arctic sea-ice,” p. 328 AND Figure 11.21, “Comparison of Arctic winter sea ice,” p. 329.

c. Sea Level Rise – UN Reports suggest that global warming and rising sea levels will continue for centuries, even if greenhouse gas emissions are slowed or reduced.  We will likely experience a temperature increase of about 0.5 degrees by 2025 regardless of what we do, but the increases start to diverge depending on the levels of emissions when you look a hundred years from now.  The report predicts average temperature increases of 1.8 to four degrees by the year 2100.  On sea levels, the report projects a rise of 17.8 centimeters to 58.4 centimeters by the end of the century.  An additional rise between 9.9 to 19.8 centimeters is possible if the recent, surprising melting of polar ice sheets continues (“It’s not like Las Vegas.  What happens in the Arctic doesn’t stay in the Arctic.” — Dr. Walter Meier, National Snow and Ice Data Centre).  The pace of global sea level rise more than doubled from 1.4 mm per year throughout most of the twentieth century to 4 mm per year currently.  (For up to the moment data, see NASA’s Sea Level Page)

  • A rise of similar size is projected to come from a combination of melt water from mountain glaciers and thermal expansion of seawater.
  • Other studies suggest this may be a conservative estimate.   NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, suggesst glacial melt is higher than previously thought.  The Greenland and Antarctic sheets were losing a combined mass of 475Gt (gigatonnes – billion tonnes) of ice per year in 2006; loss from the Greenland sheet is increasing by nearly 22Gt per year, while the much larger and colder Antarctic sheet is shedding an additional 14.5Gt each year.  If these increases persist, water from the two polar ice sheets could add 15cm (5.9 inches) to the average global sea level by 2050 and 59 cms by 2100.  (BBC News – Polar ice loss quickens, raising seas).
  • Other estimates put sea level rise at closer to 1 m over the next century (Sea level rise underestimated, say B.C. scientists – British Columbia – CBC News).  The biggest uncertainty in forecasting sea level rise is determining how quickly the polar ice sheets will melt in response to warming temperatures.
  • However sea levels not only rise from more water, but as water temperature increases, so does the volume it occupies — it expands.  This will double the overall sea level rise to 1-2 metres by 2100.  For countries like Bangladesh, eastern China, and Thailand (and even cities like Halifax, Charlottetown, and Richmond/Surrey/Delta, BC)  at sea level, this has profound consequences!  The BC government has warned builders and developers to plan for a 1 m sea level rise over the next 90 years (B.C. warned ocean will rise by 1 metre by 2100 – British Columbia – CBC News).

See also

4. Extreme Events including hurricanes and typhoons – Globally, extreme weather events and their effects are anticipated to increase.  Storm events will be more intense and result in much higher rates of precipitation in a much shorter period of time, potentially causing more floods.  For instance, the intensity, frequency and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s.  The relative contributions of human and natural causes to these increases are still uncertain.  Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.

5. Precipitation is very likely to move toward the poles, with an increase at higher latitudes and a decrease in subtropical regions.

6. Hot extremes, heat waves and drought are highly likely to become more frequent.  Wild fires will become larger and more intense as forests warm and dry.   Droughts in western Canada and the Southwest USA, and heat waves (periods of abnormally hot weather lasting days to weeks) everywhere, are projected to become more intense, and cold waves less intense everywhere.  Summer temperatures are projected to continue rising, and a reduction of soil moisture, which exacerbates heat waves, is projected for much of the western and central Canada and USA in summer. By the end of this century, what have been once-in-20-year extreme heat days (one-day events) are projected to occur every two or three years.

8. Ecosystem Changes – these changes, of course, impact natural ecosystems, especially in polar environments.

9. Acidification in oceans: Increased atmospheric carbon dioxide (up almost 40% since the pre-industrial age) will lead to increasing acidification of the ocean.  This profoundly effects marine and coral ecosystems.

10. Social and Economic Impacts: all of this has huge social, cultural, and economic costs — for nations and individuals.   For instance, with extreme weather events, rising temperatures increase, and either not enough or too much rain, there is more food insecurity. In some cases, yields of maize and wheat, for example, have increased in higher altitudes while yields of the same crops have declined in regions with lower altitudes.  One consequence is “climate change-induced displacement and migration.”  For instance, agriculture in countries such as Guatemala, Honduras, and Nicaragua is highly dependent on rainfall.  Changing precipitation patterns mean food security is undermined.   The desertification of increasing areas of North Africa and Middle East has been implicated in the economic and political instability in these areas, contributing to widespread migration.  “Climate refugees” have become a major issue in North Africa and Central Asia.

On a global scale these will have dramatic impacts that will, inevitably, affect Canada — we are part of a global community!

  • Sea level rises will flood much of the country of Bangladesh, substantial areas of eastern China, and major world cities like Bangkok — where do we as an international community — put 100,000,000+ people?  (Other low-lying areas in Asia, Europe, the Caribbean and the Americas will also be affected:  as much as 50 % of the world’s population lives within 2 metres of sea level.  Think about Canada — almost 1 million live within a metre of sea level in suburban Vancouver; Charlottetown is at sea level, as are neighbourhoods of Halifax and other coastal cities and communities).
  • What do we, as a global community, do when the Sudan, Sahara, and sub-Sahara regions of Africa become so dry as to be uninhabitable?  Desert areas in Africa, Asia, and North America will expand.  Population is also growing in these areas (like Arizona):  where do they get water?  Billions of litres of water is used to irrigate golf courses — is this ethical?
  • How do we, as Canadians, respond to increasing international demand for our fresh water resources (as the southern U.S.A. becomes hotter, drier — and more densely populated, our water, rather than our oil, may be coveted by our neighbors to the south)?
  • As extreme weather events become more common, how do we respond to more frequent catastophes?
  • Major economic implications, especially for poorer country:  “Adverse effects of global warming are “tilted against many of the world’s poorest regions” and likely to undermine development efforts and goals.”
  • This increase in stress, poverty, and displacement has serious security implications:
  • These are not “other people’s problems.”  They will become all of ours!  Do they have ethical issues for Christians?  What are the implications for missions?  These are questions the Christian community must begin to take seriously!
  • One interesting study notes that Richer Canadians emit far more greenhouse gases than lower income people:  “The richest 20 per cent of Canadian households spew almost twice — 1.8 times — the greenhouse-gas emissions of the country’s lowest income-earners … The report says the top one per cent of households had emissions three times the average and almost six times those of households in the bottom 10 per cent …  The report’s author, economist Marc Lee, says the rich can reduce emissions — taking steps like cutting air travel and investing in home energy efficiency — more easily than low-income families, without affecting basic needs.  Lee says climate policies have to be fair to be effective, and he contends high-income Canadians should bear the greater burden of reducing greenhouse-gas emissions.”  Are there some justice issues we need to wrestle with here?

Canada Effects

Climate change in Canada is a starting place for information on all issues related to climate change in Canada including emissions, impacts on both the natural environment and people, and mitigation efforts.

  • The costs to Canada — in terms of effects on key industries (like forestry and agriculture, through drought and fires), land flooded, dwelling damages, and health problems/deaths from air quality and temperature changes — are huge.
  • From
  • “As a northern nation, Canada is a key barometer for climate change. Over the past 50 years, average temperatures in this country have risen by 1.2°C, almost twice the global rate. The Mackenzie Basin in the Northwest Territories is one of three climate hot spots in the world, along with Lake Baikal in Siberia and northwestern Alaska.
  • “After decades of debate, the world’s scientific community generally agrees that the winds of climate change are sweeping our planet. But what does “climate change” really mean?
  • “Changes in the Earth’s climate are a natural and cyclical phenomenon. Historically, the climate has fluctuated between warmer and colder conditions, such as the ice ages. The greenhouse effect — the rise in temperature on Earth when gases in the atmosphere, such as water vapour, carbon dioxide, methane and nitrous oxide, trap and reflect heat back toward the Earth’s surface — is also a natural occurrence. Without it, the average temperature on Earth would be a frigid -18°C.
  • “Daily human activities, such as burning fossil fuels to drive our cars or heat and cool our homes, are precipitating changes in these natural systems. Increased concentrations of greenhouse gases are intensifying the greenhouse effect, which may cause the planet to warm up at a rate never before experienced in human history. It is already resulting in changing weather patterns worldwide and more frequent extremes in weather, such as hurricanes and droughts. Global warming, which strictly means an increase in the world’s mean temperature, is often defined under popular usage as warming caused by human activity.
  • “The changing climate is also altering the Canadian landscape and will touch Canadians in every aspect of their lives, from ski conditions to air quality. This thematic highlights major shifts and what the future may hold in Canada’s five main regions, taking into account the degree of uncertainty in climate change projections. It also broaches the question of how Canadians will have to adapt to their changing surroundings.
  • Warming on average in Canada would increase four to six degrees Celsius, with a smaller change in the south and an increase of 10 degrees in the north (over the next century).
  • Environment Canada has completed a an assessment of the social, biological and economic impacts of climate change on the different regions of Canada.  Climate experts from government, industry, academia and non-government organizations were brought together to review existing knowledge on climate change impacts and adaptation, identify gaps in research, and suggest priority areas where new knowledge is urgently needed.
  • The impacts of a changing climate are already evident in every region of Canada. Unequivocal are the impacts of climate change on many physical and biological systems, such as ice and snow cover, river, lake and sea levels, and plant and animal distributions. In addition, increases in the occurrence of heat waves, forest fires, storm-surge flooding, coastal erosion and other climate-related hazards are consistent with observed climate trends.

Some observed impacts of changing climate on physical and biological systems in Canada

  Glacier cover – mass and area; widespread reductions with local variability
  • widespread retreat since late 1800s in western Canada, since 1920s in Arctic
  • glaciers in BC are currently retreating at rates unprecedented in the last 8000 years
  • estimated loss of ice mass in Canadian Arctic of 25 km3/a for period 1995–2000
  Snow cover – reduced annual extent and duration
  • 10% decrease in extent in Northern Hemisphere for period 1972–2003
  • decrease of 20 days in duration of snow cover in Arctic since 1950
  Sea-, lake- and river-ice cover – reduced extent and duration
  • 3% per decade decrease in annual average area of sea ice in Northern Hemisphere for period 1978–2003
  • reduction of ice cover season on Great Lakes by 1–2 months during past 150 years
  Permafrost conditions – warming and deepening of annual thaw layer
  • most significant warming in western Arctic
  • 1°C increase in surface permafrost temperature since 1990 in northern Quebec
  • increase in summer thaw penetration in the 1990s
  River and lake levels – changes in water levels and timing of peak flow events
  • decline in summer and fall runoff in Prairies, leading to lower lake and river levels at those times
  • trend towards earlier spring runoff
  Plant phenology – events occurring earlier
  • 26-day shift to earlier onset of spring over the past century in Alberta
  • 5–6 day advance since approximately 1959 in the onset of phenological spring in eastern North America
  Plant productivity–
lengthening growing seasons and increased productivity
  • greater productivity rates of spruce and poplar in Quebec
  • lengthening of growing season for crop production
  Distribution of some animal species – northward or upslope shifts in terrestrial ecosystems, shifts towards warmer thermal regimes in freshwater ecosystems
  • increasing abundances of cool and warm water fish species relative to cold water species
  Coastal erosion – enhanced as a result of decreased ice cover, sea-level rise, increased storminess, and non-climatic factors
  • accelerated erosion and degradation of the dunes and coastline throughout the southern Gulf of St. Lawrence, northeastern Prince Edward Island and southwestern, western and eastern Newfoundland
  • Many of these impacts directly influence human systems. For example, decreases in the thickness and duration of lake and river ice have significantly impacted the viability of many winter road networks that provide access to remote communities and mine sites in northern Canada, while coastal erosion has impacted buildings and critical infrastructure, and threatened cultural sites on all of Canada’s marine coasts. There is also strong evidence that climate change has been a contributing factor to a number of other environmental, social and economic issues.
  • Impacts of recent extreme weather events highlight the vulnerability of Canadian communities and critical infrastructure to climate change.
  • The economic costs resulting from extreme weather events in Canada in the past decade and a half have been greater than for all previous years combined. Costs reaching hundreds of millions and even billions of dollars are associated with flooding, wind, hail and ice storms, hurricanes, tornados and wild fires in all regions of southern Canada, arising from property damage and disruptions in the production and flow of goods and services. Prolonged periods of unusual weather, such as drought, can also result in high economic costs.
  • Recent costly weather events in Canada, NOT including drought:
    • 2016: Fort McMurray Wildfire:  $9.9 billion
    • 1996: Calgary hailstorm (Alberta):  $300+ million
    • 2005: Southern Alberta floods:  $400+ million
    • 2010: Calgary hailstorm:  $400+ million
    • 2005: Toronto extreme rain (Ontario):  $500+ million
    • 2009:  Central Alberta hailstorm:  $500+ million
    • 2003: British Columbia/Alberta wildfires: $700+ million
    • 2011: Slave Lake wildfire (Alberta):  $700+ million
    • 1997: Red River flood (Prairies):  $817 million
    • 1991: Calgary hailstorm:  $884 million
    • 2013:  Toronto thunderstorm/flood:  approximately $1 billion
    • 2011:  Southern SK, MB flooding (Prairies):  $1+ billion
    • 1996: Saguenay flood, (Quebec):  $1.7 billion
    • 2013:  Southern Alberta Floods: $3-5 billion estimates
    • 1998: Ice storm, (Ontario, Quebec, Atlantic Canada):  $5.4 billion
    • 2010:  BC wildfires:  $230 million
    • 2009:  Hamilton thunderstorms (Ontario):  $200-300 million
    • 2003: Hurricane Juan (Atlantic Canada):  $200+ million
    • One issue in the news recently is the decreased potential electrical-generation energy available from hydro-electric dams.  Bridge Glacier, in BC, which supplies dams producing the 3rd largest amount of hydro-electric energy in the province, is retreating 200m per year. This has already reduced the amount of water available for hydro-electric power generation.  The amount of electricity potentially available from hydro-electricity in BC will only continue to shrink — even as demand for electricity increases.

Here are some of the highlights of regional reports (non-italicized portions from Environment Canada, italicized selections from Royal Canadian Geographical Society):

British Columbia/Yukon/Rockies

  • Significant impacts in British Columbia and the Yukon would include increased flood dangers in some areas, drought in others, and widespread disruption to forests, fisheries and wildlife.
  • Sea levels are expected to rise up to 30 cm on the north coast of British Columbia and up to 50 cm on the north Yukon coast by 2050, mainly due to warmer ocean temperatures. This could cause increased sedimentation, coastal flooding and permanent inundation of some natural ecosystems, and could place low-lying homes, docks and port facilities at risk.
  • “The expected rise in sea level, caused by melting glaciers and the expansion of ocean waters as they warm, will affect parts of coastal British Columbia, particularly in the Fraser Delta and portions of Vancouver, Victoria and the Queen Charlotte Islands. The heavily populated Fraser Delta is one of the most vulnerable regions on the Pacific Coast since parts of the lowlands already sit below sea level and are protected from flooding by an extensive dyke system. Rising seas could drown tidal marshes, havens for waterfowl, shorebirds and salmon fry. They could also flood prime farmland, industrial and residential urban areas. The intrusion of salt water would affect groundwater supplies.
  • “Climatologists predict that winters in coastal British Columbia will be wetter and stormier. In a region defined by mountains, that means unstable slopes and more frequent landslides. Heavy rains can unleash “debris flows,” a sodden mixture of mud, gravel and boulders barrelling down steep mountain stream courses. In November 2006, torrential rains washed silt into Greater Vancouver’s water supply, making tap water murky and undrinkable for about two million residents.” (

Other changes that may result from climate change include:

  • In winter, increased winter precipitation (more violent winter storms), permafrost degradation and glacier retreat due to warmer temperatures may lead to landslides in unstable mountainous regions, and put fish and wildlife habitat, roads and other man-made structures at risk. Increased precipitation will put greater stress on water and sewage systems, while glacier reduction could affect the flow of rivers and streams that depend on glacier water, with potential negative impacts on tourism, hydroelectric generation, fish habitat and lifestyles.  (This was evident in the winter of 2006-2007 as snow, rain, and wind severely damaged coastal BC, including Stanley Park)
  • Spring flood damage could be more severe both on the coast and throughout the interior of British Columbia and the Yukon, and existing flood protection works may no longer be adequate.
  • Summer droughts along the south coast and southern interior will mean decreased stream flow in those areas, putting fish survival at risk, and reducing water supplies in the dry summer season when irrigation and domestic water use is greatest. (The summers of 2005-2006, 2016-2017 were among the hottest and driest on record).
  • Glacial retreat in the Coast and Rocky Mountain systems could mean the large-scale loss of most alpine glaciers by 2050.  This would have ecosystem, water storage, hydro-electric energy, and tourism impacts.  There are about 15,000 glaciers in British Columbia. In 1985, they covered 28,800 square kilometers. By 2005, they covered 25,000, a loss of 3,000 square kilometers, or about 11 per cent.
  • warmer winters permit survival and spread of insects including pine beetles and mosquitoes carrying West Nile Virus.
  • British Columbia has been dependent on snowpack to provide moisture through the spring and summer, but it may get more rain in winter, which would run off the land rather than melting slowly as snow does. Then early springs and hotter summers could mean the moisture dries up more quickly.  However, since those regions don’t usually have to rely on reservoirs, the ones they have aren’t adequate to offset the lack of rain. In fact, the shortage has prompted water restrictions in the province and instances of hydrological drought, which is when lakes, rivers and ground water supplies are depleted.


  • Current models suggest that climate change could result in increased air temperatures and decreased soil moisture. Most scenarios suggest that the semi-arid regions of the Prairies can expect an increase in the frequency and length of droughts.
  • All three Prairie provinces, stretching from the Rocky Mountains to the shore of Hudson Bay, are vulnerable to drought.  As summer temperatures rise, the risk of drought across Alberta, Saskatchewan and even Manitoba will grow.  Alberta’s new normal could be drought.
  • Some of the potential impacts of these changes include:
  • Average potential crop yields could fall by 10-30% due to higher temperatures and lower soil moisture. However, higher temperatures could lengthen the growing season, and may increase crop production in northern regions where suitable soils exist. Crop production may need to shift to more drought-tolerant crops.  Dry-land farming may cease to be viable in southern regions, putting more pressure on limited water resources.
  • rivers are usually filled with glacial melt in the summers, but with much less glaciers and earlier melting, you might expect those rivers to be much lower, resulting in less water for irrigation when it’s needed. However, when storms happen, more sudden, more severe rainfall events can be expected resulting in major flooding.
  • Increased demand for water pumping and summer cooling, due to drought, and decreased winter demand due to higher temperatures, could push electrical utilities into a summer peak load position at the same time as hydropower production is reduced by decreased water flow. This could result in increased thermal power production with an increase in fossil fuel consumption and greenhouse gas emissions.
  • Semi-permanent and seasonal wetlands could dry up, leading to reduced production of waterfowl and other wildlife species.
  • “After Canada’s North, the southern Prairies are the region most affected by the shifting climate. Since the 1940s and early 1950s, the length of the growing season on the Prairies has grown by approximately 10 to 15 days. There is less snow cover and spring runoff begins earlier. Most climate change models suggest that the semi-arid zones of the Prairies will be more prone to drought as the weather warms. Grasslands and aspen parkland of the southern Prairies could expand northward, in tracts now occupied by the boreal forest.
  • “Glaciers along the eastern slopes of the Rocky Mountains, which feed rivers throughout the Prairies, have shrunk by an average of 25 percent over the last century, reducing downstream flows. Total glacial cover is nearing the lowest level in 10,000 years. If glaciers continue to shrink, it will exacerbate water shortages and drought, particularly in southern Alberta and Saskatchewan.” (


  • Temperature changes will be most notable near the poles — a rise of 6-10 degrees C within the next century is realistic.
  • “The Canadian Arctic is on the front lines of global warming. The North and its residents have been aptly described as the “early warning system for the entire planet.” Indeed, temperatures in the Western Arctic are among the fastest rising on Earth. Over the past 40 years, average temperatures in the Mackenzie Basin have increased by 1.5°C; by the second half of the 21st century, scientists predict temperatures in the Northwest Territories will be at least 5°C warmer than they are now.
  • “The very essence of the land of snow and ice is melting away. The polar ice cap has been shrinking at a rate of nine percent per decade since the 1970s, according to recent NASA estimates. If this trend continues, some scientists say the summer sea ice cover may completely disappear by the end of the century. Others say it could happen as early as 2050. Meanwhile, an ancient ice shelf tore away from Ellesmere Island in 2005, creating a 66-square-kilometre island. Scientists suspect the breakup was caused by global warming.
  • “Sea ice in the Arctic is not only shrinking in size, it is getting thinner. More open water means stronger waves lapping at the shoreline and causing destructive erosion, particularly along the Beaufort Sea coast. Erosion and rising sea levels are already threatening Tuktoyaktuk, a major shipping port in the Canadian Arctic.
  • “Much of the land in Canada’s northern reaches is underlain by permafrost, ground that remains frozen year-round. In recent years, melting permafrost has altered the landscape, turning parts of the hard tundra into swampy, shifting ground and increasing the risk of landslides. This is having a serious impact on many aspects of northern life, from the safety of ice roads to the instability of buildings, airstrips, pipelines and municipal water supply.” (
  • In the past 100 years, the Mackenzie district has warmed by 1.5°C and the Arctic tundra area by 0.5°C, while the Arctic mountains and fjords of the eastern Arctic have cooled slightly. Future winter temperature increases of 5-7°C over the mainland and much of the Arctic Islands and modest cooling in the extreme eastern Arctic are projected. Summer temperatures are expected to increase up to 5°C on the mainland, and 1-2°C over marine areas. Annual precipitation is expected to increase up to 25%.
  • These changes in temperature and precipitation would have dramatic effects on tundra and taiga/tundra ecosystems, reducing them by as much as two thirds. More than one half of the discontinuous permafrost area could disappear, with marked surface instability in the short term.
  • Wildlife would also be affected, with many species of fish and streams shifting northward 150 km for each degree increase in air temperature and High Arctic Peary caribou, muskoxen and polar bears running the risk of extinction.
  • Climate change would also extend the shipping season in the Arctic, while rising sea levels in the Beaufort Sea areas would endanger coastal infrastructure.


  • Ontario could experience anywhere from 3-8°C average annual warming by the latter part of the 21st century, leading to fewer weeks of snow, a longer growing season, less moisture in the soil, and an increase in the frequency and severity of droughts.
  • Other impacts of climate change could include:
  • more days when heat stress and air pollution adversely affect people’s health;
  • likely increases in the frequency and severity of forest fires; and
  • changes to aquatic ecosystems and alterations to wetlands.
  • As well, water levels in the Great Lakes could decline to record lows by the latter part of the 21st century, reducing shipping capacity.
  • “Low water levels are a major concern along the Great Lakes and the St. Lawrence River, the urban and industrial heartland of Canada. (One-quarter of Canada’s population lives in the Great Lakes region and nearly half of the country’s industries are based there, while more than 70 percent of Quebec’s population lives along the St. Lawrence.) Climate models predict that by 2050 lake levels could be lower by more than one metre.
  • “Lower water levels would have a significant impact on a variety of economic activities, from hydro power production to tourism. Maintaining navigability on the St. Lawrence Seaway could require more dredging. Shipping costs would increase as ships would have to make more trips with lighter loads. Wetlands could dry out, affecting wildlife and fisheries. Water quality may deteriorate as warmer water temperatures create a favourable environment for microbes and algal blooms.” (


  • Quebec is the most aggressive province in terms of combating climate change.
  • If carbon dioxide levels were to double, Quebec would experience average temperature increases of 1-4°C in the south and 2-6°C in the north. Precipitation would likely remain the same or decrease slightly in the south, while increasing 10-20% in the north.
  • Likely consequences include:
  • lower water levels in the St. Lawrence River, which will affect shipping, navigation, and the marine environment of the river; and
  • positive effects on agriculture, including a longer growing season and the extension of agriculture further north.


  • Climate change in the Atlantic region has not followed the national warming trend of the past century, and, in fact, a slight cooling trend has been experienced over the past 50 years. This trend is consistent with projections by climate models.
  • Hurricanes and severe precipitation events could become more frequent and more intense.
  • Atlantic Canada is particularly vulnerable, however, to rising sea levels, whose impacts could include greater risk of floods, coastal erosion, coastal sedimentation, and reductions in sea and river ice.
  • Many coastal communities are within a few metres of sea level — a rise of up to a meter in sea level would have dramatic consequences.
  • Other potential impacts include:
    • loss of fish habitat;
    • changes in ice-free days, which could affect marine transportation and the offshore oil and gas industry; and
    • changes in range, distribution and breeding success rates of seabirds.
  • “On the East Coast, climate change may intensify an existing problem of rising sea levels due to the sinking of the Earth’s crust. Much of Nova Scotia, for instance, is steadily subsiding. Sea levels at the Bay of Fundy are rising by about 40 centimetres per century. More than 80 percent of the coastlines of Nova Scotia, New Brunswick and Prince Edward Island — including the cities of Charlottetown and Saint John, N.B. — are considered moderately to highly sensitive to flooding and erosion caused by the rising sea. Coastal bluffs are retreating, some up to 12 metres in a year. Tidal salt marshes, which are critical ecosystems, could be submerged as well as dykes protecting areas that are currently below the high tide mark.
  • “Tourism will bear the brunt of the changing climate if popular natural attractions, such as coastal dunes on the north shore of Prince Edward Island and icebergs along the coast of Newfoundland and Labrador, are altered. The combined effects of rising sea levels, decreased sea ice and increased wave action could ruin the dunes. Icebergs, which normally melt in warmer waters near the southern fringe of the Grand Banks, would disappear farther north. This would be bad news for tourism operators in Newfoundland, but likely welcomed by the oil industry, which must maintain expensive engineering on its offshore oil production platforms to deal with iceberg collisions.” (

    Christians and Climate Change …

Worth reflecting on …

Sir John Houghton, former IPCC council member and Christian layperson, describes the dramatic changes that climate change will bring to Africa.  How will Climate Change impact Africa? – YouTube

2. In an online article entitled, “Climatology Reveals Creation Clues,” Susan Hanks Mowen profiles Kevin Birdwell.  Here are some interesting excerpts:

“By day, climatologist Kevin Birdwell seeks answers to mysteries of human history via climatological records. By night, he uses that research to enhance his teaching at a Christian college. Studying ancient weather at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee intrigues Birdwell “because it reveals so much about the intricacies of Earth’s ability to support life.” And, the way these discoveries affirm the Christian faith stimulates his enthusiastic pursuit of more new evidence.

“Some people think climate change is a modern phenomenon, but it’s not.” Birdwell’s passion and curiosity become contagious as he discusses one of the great mysteries of climatology. “Around 4,100 years ago a major discontinuity appeared when the entire tropical climate system around the world appears to have shut down. The land around the Mediterranean Sea used to have a lot of trees, but it became mostly rocky hills. Egyptians saw the Nile dry up and the Sahara grasslands where hippos once roamed turned into the Sahara Desert. The Old Testament mentions of major droughts such as the one of Joseph’s era (Gen. 41-47), among others, seem consistent with this paleoclimate evidence. Dramatic climate change provides a powerful time marker in Earth’s history.”

“Archaeology uncovers additional evidence for the Christian faith. “During the ice age, at least 11,000 years ago, sea levels were as much as 200 feet lower, which means a lot more land was exposed. Humans likely settled along those coasts, which are now under water.” Exploration of such inaccessible areas is costly, but if it takes place, Birdwell believes scientists will gain some significant Bible-affirming data about human history.

“Such discoveries often validate the Bible’s statements. The more I get into the study of climate and its history, the more I find out about human history and how it fits into the biblical story.”

“To further enhance his knowledge and goals, Birdwell is currently working toward a University of Tennessee (UT) Ph.D. in geography with specialties in climatology, environmental geography, and air quality. “I have talked about divine design evidences with professors and fellow students. Although many of them are committed to a naturalistic viewpoint, several have been impressed with the data I present,” Birdwell said. “One of the most-encouraging comments I received came from an evolutionary biology major who said he would have to think about these matters. Given his depth and perspective, that meant a lot.”

“Climatology continues to provide evidence for God’s wisdom and power, increasing Birdwell’s appreciation for the creation and Creator. And, that appreciation keeps him busy sharing with others how science fits with Scripture.”

Read the whole article (and more) at  Reasons To Believe : Climatology Reveals Creation Clues

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Scripture quotations marked (NLT) are taken from the Holy Bible, New Living Translation, copyright © 1996. Used by permission of Tyndale House Publishers, Inc., Wheaton, Illinois 60189. All rights reserved

La Nina:  By NASA image by Jesse Allen, using AMSR-E data processed and provided by Chelle Gentemann and Frank Wentz, Remote Sensing Systems. [Public domain], via Wikimedia Commons