The Earth’s climate has always been in a state of flux. In the past it has altered as a result of natural causes, such as during the great ice ages. Today, climate change is generally used to describe climatic variation over the past 100 years or so. There is increasing scientific consensus that these changes, and those predicted for the rest of the 21st Century, are largely the consequence of human activity, rather than due to natural changes in the atmosphere.
The overwhelming majority of scientists believe it is the extra greenhouse gases that humans have released that are the greatest threat to the climate.
The main sources of man-made greenhouse gases are:
- burning of fossil fuels in electricity generation, transport, industry and households,
- agriculture and land use changes like deforestation,
- land filling of waste,
- use of industrial fluorinated gases.
Rising fossil fuel burning and land use changes continue to emit increasing quantities of greenhouse gases into the Earth’s atmosphere. These greenhouse gases include carbon dioxide (CO2), methane (CH4) and nitrogen dioxide (N2O). An increase in these gases has caused a rise in the amount of heat from the sun withheld in the Earth’s atmosphere, heat that would normally be radiated back into space. This increase in heat has led to the greenhouse effect, resulting in climate change.
The main characteristics of climate change are increases in average global temperature (global warming); changes in cloud cover and precipitation particularly over land; the melting of ice caps and glaciers and reduced snow cover; and increases in ocean temperatures and ocean acidity – due to seawater absorbing heat and carbon dioxide from the atmosphere.
The Earth's average surface temperature has risen by 0.76° C since 1850, with Europe warming faster than the average, by almost 1°C. The eleven warmest years on record have occurred since 1995.
To reduce the effects of climate change, global greenhouse gas emissions must be reduced significantly. The European Union (EU) believes climate change represents one of the greatest environmental, social, economic and health threats facing the planet. The EU is committed to working constructively for a global agreement to control climate change, and is engaged in far reaching action of its own.
The last time climate change happened at a pace similar to the current one, was 125 000 years ago and led to a 4-6 metre sea level rise (European Environment Agency) .
Scientists differ over the exact global impact climate change is likely to have this time; some claim it could cause major changes to our lives, in order to adjust to a warmer planet, others believe that it could be catastrophic for the planet.
The Intergovernmental Panel on Climate Change (IPCC) was set up in 1988 to assess information on climate change and its impact.
Generally, there is a political consensus that global average temperatures should not exceed 2°C above pre-industrial level, in order to avoid severe consequences.
The IPCC’s Fourth Assessment Report projects that unless there is concerted global action to reduce greenhouse gas emissions, the global average surface temperature is likely to rise by a further 1.8-4.0°C by the year 2100, and by up to 6.4°C in the worst case scenario:Warming of the climate system is unequivocal, as is now evident from observation of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level (IPCC).
Projected global warming this century is likely to trigger serious consequences for mankind and other life forms, including a rise in sea levels of between 18 and 59 cm which will endanger coastal areas and small islands. Extreme weather events are likely to increase in intensity and frequency.
If climate change continues and is not rapidly reversed, mainland Europe could suffer greatly from flooding, with many major ports and cities at risk of disappearing eventually. Rises in temperature could damage agriculture in southern European climates and take a toll on human life.
But developing countries in Africa, Asia and Central and South America are projected to suffer the greatest consequences of climate change. In these regions, poor countries already prone to high temperatures, drought and food shortages will be particularly vulnerable. Many of these countries will be unable to fund initiatives to deal with climatic disaster.
- 1. Introduction
- 2. Global response
- 3. EU´s response
- 4. Support to the developing world
- 5. Technological response
- 6. Key policy makers and contacts