Climate Change Basics

The scientific community agrees – climate change is happening and human activity is almost certainly the cause. In the last 100 years the Earth has warmed by 0.74°C (and by 0.4°C since the 1970s), meaning that global sea levels have gone up, glaciers and sea ice has melted, floods and droughts are on the increase, and heatwaves are worse. Moreover, we are committed to further unavoidable climate change from this past rise in temperature, including further sea level rises for centuries to come.

The greenhouse effect

The term ‘greenhouse effect’ was coined to describe the way some gases in the atmosphere (such as carbon dioxide, nitrous oxide, and methane) trap some of the light energy from the sun after it is reflected from the Earth's surface, and  before it can escape out into space, so warming our atmosphere. This is a natural process that has been happening for billions of years, and without it the Earth would be about 33°C colder – too cold for us to live on. Now, however, human influence has upset the natural balance of carbon dioxide and other greenhouse gases and too much of the sun’s energy is being trapped, causing average temperatures to rise.

High levels of CO₂

Human greenhouse gas emissions have gone from practically nothing to tens of billions of tons per year since the start of the industrial revolution. At present, over 30 billion tonnes of carbon dioxide (CO₂) is emitted globally each year by burning fossil fuels, and another seven billion tonnes by changes of land use, mainly deforestation.

Here is a really great interactive tool which shows what could happen at 4^oC rise: Met Office Map

The government's guide to climate change and global warming is here to view or download below:

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Met-Office-climate-change-guide.pdf	1.34 MB