Through human activities such as burning fossil fuels, atmospheric CO2 concentration has increased by more than a third since the Industrial Revolution. The increase in the concentration of greenhouse gases is blocking heat from escaping Earth, “forcing” climate change. Approximately 36 per cent of US CO2 comes from burning coal, oil and gas to produce electricity, making the sector the largest source of emissions.
Before 2005, US CO2 emissions were rising year-on-year, peaking at just below 6,000 million tonnes. With a growing population, emissions should have continued to increase. Instead, in the US carbon dioxide emissions have fallen by 14 per cent in the last decade. What has caused this sudden change, and is it enough to offset the effects of climate change?
A tale of many parts
There is no single factor that caused the reduction in CO2. Emissions fell in the US because of a combined move towards: natural gas and renewables; a reduction in energy usage and reduced emissions from non-electric sources.
The gradual switch from coal towards natural gas was responsible for the largest share in emissions reduction. While far from carbon free, natural gas has become a cheaper alternative to coal, reducing CO2 simply by producing less emissions.
While natural gas led the charge, the increase of wind and solar power also plays a part in reducing CO2 emissions. Together, wind and solar now represent 22 per cent of the US’ energy industry, a number that is rising at a steady rate.
The worthy cause
Unless politics interfere with the ongoing transition to natural gas, carbon emissions are predicted to continue declining. However, while curbing CO2 emissions is helping to reduce the likelihood of climate change, it is not enough to offset increasing global temperatures entirely.
While a 14 per cent reduction in US emissions over the last ten years is important in fending off climate change, the current rate is not sufficient. If the global temperatures rise by just 2° Celsius above pre-industrial levels, there could be an increase in forest fires, extreme weather, drought and other significant consequences.