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Brussels, 2 February 2007
Climate change: New report from the world's leading
scientists underlines the need for urgent global
action
European Environment Commissioner Stavros Dimas called for an urgent
start to international negotiations on a comprehensive new global climate
change agreement following today's publication of alarming scientific
evidence by the Intergovernmental Panel on Climate Change (IPCC). The
consensus report from IPCC Working Group I (WG1) projects that, without
more action to limit greenhouse gas emissions, the global average
temperature is likely to rise by a further 1.8-4.0°C this century, after
increasing by over 0.7°C in the past 100 years. Even the low end of this range
would take the temperature rise since pre-industrial times to above 2°C, the
level at which there could be irreversible and possibly catastrophic
consequences. The pace of global warming and sea-level rise has increased.
The recent observations and measurements reflected in the report dispel any
doubts that the global climate is changing and that human activities have
caused most of the changes observed in the past 50 years.
Commissioner Dimas said: "I am deeply concerned at the accelerating pace and the
increasing extent of climate change that it shows. It is now more urgent than ever
that the international community gets down to serious negotiations on a
comprehensive new worldwide agreement to stop global warming. To stabilise global
emissions of greenhouse gases, the next step must be for developed countries to cut
their emissions to 30% below 1990 levels by 2020, as the Commission proposed last
month.”
Main report findings
The WG1 report, Climate Change 2007: The Physical Science Basis, assesses the
latest scientific knowledge on climate change and constitutes the first part of the
IPCC's forthcoming Fourth Assessment Report. It confirms the main findings of the
Third Assessment Report from 2001, but many results can now be better quantified
and there is even higher confidence in them.
Its key conclusions include the following:
- Warming of the climate system is unequivocal, as is now evident from
observations of increases in global average air and ocean temperatures,
widespread melting of snow and iceand rising sea level.
- It is “very likely” that increases in man-made greenhouse gas emissions have
caused most of the rise in globally averaged temperatures since the middle of
the 20th century. It is “extremely unlikely” that this warming was due to natural
climate variability alone.
- During the last 100 years the Earth has warmed by 0.76°C on average, and the
rate of warming has further increased. The 11 warmest years on record have all
occurred in the last 12 years. The second half of the 20th century was the
warmest period in the northern hemisphere for at least 1,300 years. Europe has
warmed by about 1°C over the past 100 years, faster than the global average.
- Based on scenarios that assume no further action is taken to limit emissions,
the best estimates of the projected further rise in the global average
temperature by 2100 range from 1.8 to 4.0°C1 The full uncertainty range for
projected global warming this century is 1.1-6.4°C .
- Rates of observed sea level rise almost doubled from 18 centimeters per
century in 1961-2003 to 31 cm per century in 1993-2003.
- The concentration of carbon dioxide (CO2) and other greenhouse gases in the
atmosphere has continued to increase due to man-made emissions, and the
rate of increase has further accelerated. Current concentrations of CO2 and
methane are the highest for at least 650,000 years.
- New research indicates that plants and soils will absorb less CO2 as the world
warms. Hence, a larger fraction of the CO2 emitted will remain in the
atmosphere, and the magnitude of climate change caused by a given level of
emissions will be larger than previously thought.
- Extreme weather events have increased and regional climate patterns are
changing. Heat waves and other weather extremes, as well as changes in
atmospheric circulation patterns, storm tracks and precipitation, can now be
traced back to climate change caused by human activities.
- Scientists have improved their ability to predict future climate change.
Confidence in regional climate change projections has increased due to better
models and more powerful computers. The temperature over land and at high
northern latitudes will be higher than the global average. In the Arctic it could be
on average 6°C – and possibly as much as 8°C - warmer by the end of this
century than at the end of the 20th.
Background
The IPCC assesses the scientific, technical and socio-economic information relevant
for understanding the risk of man-made climate change. Its regular reports are based
mainly on peer reviewed and published scientific and technical literature. The
assessments are produced by three working groups which bring together hundreds
of leading experts from around the world. The reports thus represent the most
authoritative global scientific consensus on climate change.
Research projects funded under the EU's Framework Programmes on research, as
well as under research programmes by individual Member States, have contributed
significantly to the WG1 report.
Further information at www.ipcc.ch
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The European Union’s objective is to limit global warming to no more than 2°C above preindustrial levels because the risks of irreversible and possibly catastrophic changes
greatly increase beyond this threshold. Greenhouse gas concentrations in the
atmosphere are currently around 425 ppm CO2-equivalent and rising at 2-3 ppm every
year.
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