Heat is radiated back towards space, but some gets trapped by greenhouse gases in the atmosphere.
In order to prevent dangerous climate change, we must limit global average temperature rise to 2°Celsius.
If we do not act now, scientists expect that the temperature will continue to increase, causing the climate to change and our environments to be affected.
CO2 is essential to life on Earth, but we need to avoid increasing the concentration of this gas in the atmosphere.
Greenhouse gases, including CO2, prevent some of the sun's heat from escaping back into space, keeping the Earth warm enough for plants and animals to survive. The greatly increased amount of CO2 in the atmosphere resulting from human invention and industrialisation, however, is causing the Earth’s temperature to rise rapidly.
Global CCS Institute
Greenhouse gases in our atmosphere have increased since pre-industrial times.
This increase of greenhouse gases (including carbon dioxide, methane, and nitrous oxide) is due to fossil fuel use, deforestation, land use change and agriculture. These rates of increase are unprecedented in the last 22,000 years.
Source: Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report on Climate Change
Since the 1950s there have been a number of unprecedented changes to the climate.
The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.
Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report on Climate Change
Fossil fuels include coal, oil and natural gas.
Emissions from these fossil fuels occur when they are used to provide energy, or in industrial processes such as the manufacture of steel, cement or fertiliser. These fuels are also finite, meaning that they are not replenished and will eventually run out.
The world's consumption of energy will grow by 56% between 2010 and 2040.
Globally, economic and population growth continue to be the most important drivers of increases in CO2 emissions from fossil fuel combustion.
Source: Climate Change 2014: Mitigation of Climate Change, IPCC WGIII (http://www.mitigation2014.org/)
The world will continue to use fossil fuels for many years to come.
Fossil fuels are expected to continue to supply almost 80% of the world’s energy use in 2040.
US Energy Information Administration International Energy Outlook 2013 (IEO2013)
International organisations and governments are working on solutions
Organisations such as the United Nations Framework Convention on Climate Change, the Intergovernmental Panel on Climate Change, the International Energy Agency, as well as national governments from around the world are working on solutions to the climate challenge. Governments have agreed to limit global warming to 2 degrees above pre-industrial times.
The 2 degrees challenge is crucial in avoiding dangerous climate change.
In order to achieve the 2 degrees challenge, we must cut energy-related emissions by more than half in 2050 (compared to 2009). This involves limiting the concentration of greenhouse gases in the atmosphere to around 450 parts per million of CO2.
International Energy Agency, Energy Technology Perspectives
The good news is there are a number of solutions available to avoid dangerous climate change by reducing CO2 emissions.