The first consequences of climate change can already be seen in Europe and worldwide, and these impacts are predicted to intensify in the coming decades. Temperatures are rising, rainfall patterns are shifting, glaciers are melting, sea levels are getting higher and extreme weather resulting in hazards such as floods and droughts is becoming more common.
These changes pose a serious threat to human lives, to economic development and to the natural world on which much of our prosperity depends.
Global temperatures have risen by some 0.75º C over the past 100 years. The average global temperature is projected to increase further by anywhere between 1.1ºC and up to 6.4ºC over the course of this century unless the world takes action to limit the concentration of greenhouse gases in the atmosphere.
An increase of 2° C above the temperature in pre-industrial times (around 1.2° C above today's level) is seen by scientists as the threshold beyond which there is a much higher risk that dangerous and possibly catastrophic changes in the global environment will occur.
But even below this level climate change will have significant impacts.
The world's oceans are warming up, expanding their volume. Polar ice sheets have started to melt and glaciers around the world are shrinking. The combination of these changes is increasing sea levels, which in time will threaten low-lying land areas and islands.
As the climate changes, extreme weather events like heat waves, droughts heavy rain and snow, storms and floods are becoming more frequent or more intense.
Rainfall patterns are also changing. In Europe the Mediterranean area is becoming drier, making it even more vulnerable to drought and wildfires. Northern Europe, meanwhile, is getting significantly wetter, and winter floods could become common.
Climate change is expected to cause significant changes in the quality and availability of water resources.
Vulnerability to climate change varies widely across regions. Many poor developing countries are among the most vulnerable to climate change but also have the least resources to cope with it.
European regions that are particularly vulnerable to climate change include:
Extreme weather events such as heat waves and floods pose a direct risk to the health and safety of people, with the very young, the elderly, the disabled and low-income households particularly vulnerable.
Damage to property and infrastructure imposes heavy costs on society and the economy. Sectors that rely strongly on certain temperatures and precipitation levels, such as agriculture, forestry, energy and tourism, will be particularly affected.
Climate change is happening so fast that many plant and animal species will struggle to cope. Warming of 1.5º C-2.5º C beyond today's levels would put as many as 20-30% of plant and animal species at increased risk of extinction.