Climate researchers use every available direct and indirect measurement to study the full history of Earth’s climate. This includes the latest satellite observations and samples of prehistoric ice extracted from glaciers. When they examine the changes over the past 100-150 years they use observations made by modern scientific instruments.

When scientists study the climate from before the past 100-150 years they use records from physical, chemical and biological materials preserved within the geological record. These materials function as climate proxies, providing valuable data and extending our knowledge of past climate back hundreds of millions of years into the past.

Some climate proxies include:

• Physical
  ice cores
  sediment cores
• Biological
  diatomes
  forams
  coral
  tree rings
• Chemical
  isotope ratios
  elemental analysis
  biogenic silica

By studying the past climate scientists can determine trends and paint the history of Earth’s climate system. These trends combine with today’s climate data to form models that represent the best predictions of what the climate will look like in the future. These predictions are used to determine the implications we may face as these changes occur, and how we can plan to adapt.

This graph outlines atmospheric concentrations of CO₂ (carbon dioxide) from 800,000 years ago to today. It provides evidence that atmospheric CO₂ has increased since the industrial revolution.

This graph outlines atmospheric concentrations of CO₂ (carbon dioxide) from 800,000 years ago to today. It provides evidence that atmospheric CO₂ has increased since the industrial revolution.

This graph provides evidence that atmospheric CO₂ has increased since the industrial revolution. Data is based on samples taken from ice cores and more recent direct measurements, (Credit: Luthi, D., et al.. 2008; Etheridge, D.M., et al.2010; Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO₂ record.)

The Earth’s climate has changed over millennia, mostly due to small differences in Earth’s orbit around the sun and the amount of solar radiation it is exposed to as a result. In the last 650,000 thousand years the Earth has gone through 7 cycles of glacial advance and retreat, with the last ice age ending abruptly around 11,700 years ago. This marked the start of the modern climate era and the beginning of human civilization.³

The modern warming trend is particularly significant because most of it is extremely likely (over 95% probability) to be caused by human activities since the mid 1900s. This extreme rate of warming is 10x faster than the average post glacial warming period and it is proceeding at a rate that is unprecedented over decades to millennia.^2,3

You’ve probably heard of greenhouse gases before, but what exactly are they and why do they matter?

Greenhouse gases are gases in Earth’s atmosphere that trap heat. They let sunlight (solar radiation) pass through the atmosphere, but they prevent the heat that comes with it from leaving the atmosphere. The main greenhouse gases are:

Some greenhouse gases in the atmosphere are essential for keeping the planet from becoming too cold. However, as you will see, when too much of these greenhouse gases build up in the atmosphere they prevent excess heat from escaping, and lead to many effects that can be disruptive to life on Earth.⁶

Carbon dioxide and methane are two of the greenhouse gases that have been building up in the atmosphere rapidly since the industrial revolution.³ The graph below outlines the carbon cycle and how carbon cycles through the biosphere, geosphere and atmosphere.

The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back to the atmosphere.

On Earth most carbon is stored in rocks and sediments. The rest cycles through the ocean, the atmosphere and in living things. These represent the carbon reservoirs, or sinks.

Carbon is constantly being released into the atmosphere. As organisms die, forests burn and volcanoes erupt, these carbon sinks send carbon into the atmosphere. As carbon builds up in the atmosphere, much of it is cycled back to the Earth where it can be absorbed by the ocean’s surface water, or sequestered by photosynthesizing plants.

The carbon cycle has been relatively stable and predictable for millennia. The major problem we face today is that far more carbon is being released into the atmosphere than the Earth’s carbon cycle can regulate. Humans play a major role in the carbon cycle by burning fossil fuels and developing land, and as a result the amount of CO₂ in the atmosphere is rising rapidly. As the carbon cycle becomes unbalanced and overwhelmed, it puts added pressure on the rest of the system to keep up. Let’s take a look at how the ocean is reacting to this increased burden.

Ocean Acidification – how the oceans are being overwhelmed by excessive CO₂

(Source: https://coastadapt.com.au/ocean-acidification-and-its-effects)

The Ocean has absorbed more than 25% of the greenhouse gas that has built up in the atmosphere — this includes CO₂.⁵ As CO₂  is absorbed it increases the acidity of ocean water, which has many detrimental effects on the organisms that live within it.

Some of these effects include:

• Coral bleaching (die off)
• Shells dissolve (shellfish die off)
• Food chain disruption — this effects economic activities such as fisheries, aquaculture and tourism.⁴

As you can see, the effects of climate change impact the land and the ocean. The entire system is interconnected! With this interconnection comes many indirect impacts of climate change. To illustrate these impacts, lets take a look at how a warmer climate is melting the polar ice caps and the feedback loops that contribute to accelerating climate change.

Melting Polar Ice Caps and Climate Change

The melting of polar ice is a fundamental example of what scientists refer to as a positive feedback loop.

(Source: The National Academies of Science, Engineering and Medicine)

Polar ice helps modulate the effects of climate change in several ways: It prevents evaporation of ocean water below the sea ice; it insulates ocean water against the atmosphere — helping to slow acidification — and it reflects the sun’s energy back into space, cooling Earth in the process.⁷ This effect of reflecting the sun’s light, rather than absorbing it, is called the albedo effect.

(Source: https://www.nasa.gov/)

As the Earth loses its polar ice, more of the sun’s energy is absorbed by the land and ocean, further warming the climate. This additional warming contributes to more ice melt, resulting in even less solar radiation being reflected into space. This cycle of ice loss leading to warming, which causes more ice loss and so on, is an example of a positive feedback loop. The global climate system is effected by many feedback loops that combine to form the interconnected nature of Earth’s geological, biological and climate systems.⁷ As these systems affect the Earth’s warming, the change in temperature affects the systems themselves. Some “downstream” effects of polar ice melting include:

• sea-level rise
• changes in ocean currents
• changes in ocean nutrient cycling and food systems

All of these changes have global implications, and it will take effort from around the world to mitigate, adapt to and overcome these challenges.

Now that we understand how climate change is studied and how it works, lets examine what effect the changing climate may have on our country and community.

(Source: https://www.amap.no/maps-and-graphics/search?keywords=arctic+ice#980)

As a northern country Canada is warming at almost double the average global rate. Over the last six decades (between 1950-2010) the average temperature over land in Canada has increased by 1.5°C. This means that a 2°C increase in global average temperature over the next century could result in a 3-4°C increase in Canada.

Along with this increase in temperature, Canada is also experiencing increased precipitation. The average annual precipitation has increased by 16% between 1950-2010. This is mostly attributed to large changes in British Colombia and Atlantic Canada.

The increase in temperature and precipitation is predicted to cause more frequent extreme weather events. A 1-in-20 year storm is likely to become a 1-in-10 year storm by the 2050s. In other words, a storm that has a 5% chance of occurring today will have a 10% chance of occurring in the 2050s.

Along with Canada as a whole, Conception Bay South is predicted to become warmer and wetter as time goes on. A temperature increase of 1.4°C between 2021-2050 and 3.2°C between 2051-2080 is expected if the current global greenhouse gas (GHG) emissions proceed in a “business as usual” way — that is, if continued economic growth without decreased emissions occurs. Furthermore, annual precipitation is projected to increase by 82mm between 2021-2050 and 124mm between 2051-2080. These changes will be accompanied by more frequent extreme weather events and more freezing rain in December, January and February.

Table 1: Climate Change Projections for Conception Bay South

Each region and community around the world have their own unique strengths and vulnerabilities when it comes to the impacts of climate change. As a large coastal community, Conception Bay South is especially vulnerable to the impacts of sea-level rise, storm surges and coastal erosion.

Translating the effects of climate change into potential risks, vulnerabilities and opportunities is what the Provincial Government sought to do with its Turn Back The Tide campaign. The table below outlines what practical impacts we may increasingly face as these changes in the climate develop over the coming decades.

 Table 2: Climate Change Projections and Impacts for Newfoundland and Labrador

So far we have learned about how scientists use chemical, physical and biological materials to study the climate of Earth as it was millions of years ago. By combining data from climate proxies with readings taken by modern instruments over the past 150 years, scientists determine the trends used to create models to make predictions about future climate conditions, and the implications we may face in the years to come.

We have also learned about greenhouse gases, and how the carbon within them fits into the Earth’s carbon cycle. You might recall how the carbon cycle illustrated the interconnected nature of Earth’s systems, and how manipulating one aspect can have downstream effects on many others. This concept was further explored in terms of ocean acidification and the melting of polar ice. These “big picture” concepts help us to begin to think of Earth in a more global way, rather than separate and disconnected parts.

Finally, we have examined what all of this could mean for Canada and our community. Warmer, wetter and wilder weather is on the horizon and it’s important to know what we can expect so we can plan how to face the challenges ahead.

So, what can we do? Fortunately, there is a lot we can do to protect ourselves and our communities against the impacts of climate change, and enable ourselves to adapt and thrive in a changing world. These actions can be divided into 3 categories:

1. Mitigate
2. Adapt
3. Educate

Mitigate — mitigation is about stopping the problem at the source. Just like preventing a fire before it starts.  We can mitigate the effects of climate change by decreasing our fossil fuel use, reducing our waste and living more sustainably. This can mean turning off the lights when you leave the room, unplugging appliances when they’re not in use, or only doing full loads of laundry. There are many small changes to our day to day habits that can allow us to live more sustainably and help us mitigate climate change. For more mitigation actions, visit the Home Sustainability page in the Sustainability Toolbox.

Adapt — adaptation is about responding to climate change impacts, increasing resiliency and our ability to overcome and even thrive in the face of challenges. In the event of a fire, adaptation would mean having an escape plan once the fire happens, and getting out of there! There are many actions we can take to adapt to climate change, such as having a home emergency kit ready or being Fire Smart. For more information on how you can adapt to climate change, visit the Home Resilience page in the Sustainability Toolbox.

Educate — Keep yourself, and those around you, informed! As much as it’s important to live sustainably and adapt to climate change impacts, it takes a village to make it work! Talk to your friends and family about climate change and what we can do to face this challenge together. Seek information from reliable sources, and stay up to date on what scientists are advising. For more information, check out the Further Information section below.

Citations

1. Parker, Wendy, “Climate Science”, The Stanford Encyclopedia of Philosophy (Summer 2018 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/sum2018/entries/climate-science/>.

2. IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

3. https://climate.nasa.gov/evidence/

4. https://www.pmel.noaa.gov/co2/files/noaa_oa_factsheet.pdf

5. https://www.pmel.noaa.gov/co2/story/Ocean%2BAcidification

6. IPCC 2007, Summary for Policymakers, in Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, UK, p. 17.

7. Meredith, M., M. Sommerkorn, S. Cassotta, C. Derksen, A. Ekaykin, A. Hollowed, G. Kofinas, A. Mackintosh, J. Melbourne-Thomas, M.M.C. Muelbert, G. Ottersen, H. Pritchard, and E.A.G. Schuur, 2019: Polar Regions. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. In press.

Further Information

Intergovernmental Panel on Climate Change:

https://www.ipcc.ch/

 Government of Canada Dept. of Environment & Natural Resources, Climate Change page:

https://www.canada.ca/en/services/environment/weather/climatechange.html

Canada’s Changing Climate Report – NRCAN

https://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/energy/Climate-change/pdf/CCCR_FULLREPORT-EN-FINAL.pdf

The Climate Atlas of Canada

https://climateatlas.ca/

World Data Centre for Greenhouse Gases:

https://gaw.kishou.go.jp/