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The Problem

Climate change affects people and nature in countless ways, and it often increases existing threats that have already put pressure on the environment.

The financial crisis is a result of our living beyond our financial means. The climate crisis is a result of our living beyond our planet’s means.

Yvo de Boer, Executive Secretary of the United Nations Climate Convention

Atmospheric concentrations of carbon dioxide, 1000–2005

When you change the climate you change everything

The climate plays such a major part in our planet's environmental system that even minor changes have impacts that are large and complex.

Climate change affects people and nature in countless ways, and it often increases existing threats that have already put pressure on the environment.

But it is not a problem which has appeared overnight – it's 30 years since scientists first alerted the world to the dangers of climate change. How much longer are we going to allow it to continue?

The change in nature has serious implications for people and our economic system. The insurance industry puts potential economic damage caused by global warming impacts at hundreds of billions of dollars each year.

The world is on course to see entire Island nations disappear as sea levels rise. In addition to the almost 1 billion food-insecure people, many more in developing countries will face food insecurity if deserts spread, if the Asian monsoon system is substantively changed, or if the freshwater supply from melting mountain glaciers such as those in the Himalayas becomes increasingly erratic. The UN’s authorized climate institution, the Intergovernmental Panel on Climate Change (IPCC), calculates that unchecked climate change will cut global food production by up to 40 per cent by 2100. 

And the 11 warmest years are...

Perhaps more disturbing is the fact that the 11 warmest years globally since 1856 have occurred in the last 15 years.

1. 1998 & 2005 (Joint)
2. 2002 & 2005 (Joint)
3. 2001
4. 1997
5. 1995
6. 1990 & 1999 (Joint)
7. 1991 & 2000 (Joint)
 
Figures compiled by the UK Meteorological Office and the Climatic Research Unit of the University of East Anglia for the World Meteorological Organization.

Global warming does not happen by default. It is a man-made problem.

CO2:  the main global warming gas

Carbon dioxide (CO2) is the most significant of the global warming gases, accounting for over 80% of global warming pollution. Atmospheric levels of CO2 are now higher than at any time in the past 420,000 years. And this is all due to human action.

CO2: mainly from coal, oil and gas

Around 97% of the CO2 emitted by western industrialised countries comes from burning coal, oil and gas for energy. We spew approximately 25 billion tonnes of CO2 into the atmosphere every year. That's about 800 tonnes every second! Not surprisingly, a global temperature build-up on this scale is seriously disrupting the natural balance of the world's climate.

 

The natural greenhouse effect

Our atmosphere naturally allows the Sun's infra-red radiation to reach the Earth's surface and warm it. The radiation bounces off the Earth's surface into the atmosphere where it is trapped by carbon dioxide, water vapour, nitrous oxide, methane and other gases (collectively known as "greenhouse gases") that are naturally present there. The trapped infra-red radiation makes the lower atmosphere and the Earth's surface warmer than it otherwise would be.

In short, the naturally-occurring greenhouse gases create a blanket-like effect, which maintains an average temperature on the Earth's surface of about 15°C.

Natural temperature variations 
Throughout history, our planet has experienced cold and warm periods naturally. These are due to variations in the Earth's orbit around the Sun, which affects the amount of sunlight reaching the Earth's surface.