What is climate change?
Climate change refers to changes in long-term weather patterns. We are currently experienced these changes as increasingly extreme weather conditions: more common severe tropical storms, droughts, flooding, and heat waves. Natural climate change occurs in cycles, exemplified by the cyclical warming and cooling that produced the ice ages of the distant past. However it is clear now that the Earth is following a man-made warming trend, rather than another warming cycle. Over the past 130 years, there has been an increase to the global temperature of about 0.85 degrees Celsius with us on track to reach a 4 degree Celsius change by the year 2100. To put that in perspective, a global temperature decrease of 4 degrees Celsius would take us to the world temperature during the ice age, where parts of Canada were under ice more than 1.5 km (0.9 mi) thick. But how did humans cause such a dramatic warming trend?
The Earth and its atmosphere act as a greenhouse. Heat and radiation from the sun hits the Earth and rebounds into space, however some of the radiation remains within the atmosphere. When greenhouse gasses (GHGs) are released into the atmosphere they absorb some of the rebounded heat effectively trapping it, like a blanket. As more and more GHGs are emitted through natural processes, or more commonly through the combustion of fossil fuels for human activities, they can capture and hold an increasing amount of solar radiation close to the Earth, leading to greater average global temperatures.
There is a misconception around the term global warming. Global warming refers to the portion of climate change that occurs due to human activities, including: carbon dioxide and other GHG emissions due to fossil fuel combustion, deforestation, use of aerosols, and wetland degradation. While average global temperatures are increasing (hence global warming), this does not mean that the temperature increase is uniform across the planet. Instead, the global increase in temperatures can drastically alter the water cycle, wind patterns, and local geography. These changes to key global processes have varying effects in different parts of the world, which is why some countries experience heat waves while others have cold waves. The changes are also responsible for increasingly extreme storm events, flooding, droughts, and cold snaps.
The role of renewable energy
From Natural Resources Canada:
Renewable energy is energy obtained from natural resources that can be naturally replenished or renewed within a human lifespan, that is, the resource is a sustainable source of energy
By this definition, renewable energy technologies are largely emission free or carbon neutral emission sources. This means that energy generated via renewable energy systems will not release any new carbon dioxide or other GHGs into the atmosphere during operation.
- To learn more about carbon neutral systems, refer to Environmental Impacts of Bioenergy.
Worldwide, carbon emissions from electricity generation account for 40% of global greenhouse gas emissions1. In New Brunswick, 60–70% of the provincial energy comes from renewable or emission-free sources2. The table below shows the carbon dioxide emissions that come from burning various fossil fuels to generate electricity:
|Fuel||kg of CO2/kWh||Pounds of CO2/kWh|
|Adapted from the United States Energy Information Administration|
|Distillate Oil (No. 2)||0.74||1.64|
|Residual Oil (No. 6)||0.80||1.76|
A monthly power bill of 1000 kWh, where 70% of the energy was generated through renewable or emission free sources, would generate about 180 kg (400 lbs.) of carbon dioxide per month. That’s equivalent to taking 2 cars off of the road for a week.
At Renewables NB, we believe that the generation of clean energy is a crucial step to be taken in order to ensure the long-term sustainability of our planet.
The causes of climate change and what you can do to help: