|
|
A vital component of the Met Office, the Met Office
Hadley Centre was opened in 1990, when the Met Office
was still in residence at its previous headquarters in
Bracknell.
What does the Met Office Hadley Centre's
work cover?
Now working out of the new state-of-the-art headquarters
at Exeter, the centre continues to produce world-class guidance
on the science of climate change and to provide a focus
in the UK for the scientific issues associated with climate
change.
|
| |
|
|
Its work includes:
- understanding physical, chemical and biological
processes within the climate system and developing
state-of-the-art climate models that represent them;
- using computer models to simulate global and regional
climate variability and change over the last 100
years and to predict changes over the next 100 years
and beyond;
- monitoring global and national climate variability
and change;
- attributing recent changes in climate to specific
factors;
- understanding the natural variability of climate
from year to year.
|
|
Sophisticated models... but not a catwalk
in sight
Computer models are the backbone of climate prediction and research.
The models currently used to make projections of the future climate
are complex and include the dynamics of both the atmosphere and
the oceans. The interactions between these are an important part
of the Earth's climate and studying the way the atmosphere and
oceans work is of utmost importance. The most sophisticated simulations
also include atmospheric chemistry, complex cycles and feedback
mechanisms which impact on climate change.
The new NEC SX-6 supercomputer - one of the world's fastest and
most powerful - came on-line at the Met Office between May and
early June, which by next year will give an increase of 12.5 times
the power of the previous supercomputer. This allows the use of
even more sophisticated models of the climate and scientists can
begin to produce estimates of uncertainty, in the form of probabilities.
These estimates are needed by governments and other decision-makers
working in the field of environmental risk assessment and management.
Future climate change
Working with five scenarios of future CO2 emissions defined
by the Intergovernmental Panel for Climate Change, experts at
the Met Office Hadley Centre have used the models to illustrate
future climate trends.
|
In mid-range CO2 emissions, the model projects:
- a global mean temperature rise of 3 °C by
the end of this century;
- a global increase in rainfall by 3.5%;
- an increase in European temperatures of around
4.5 °C;
- an increase in European rainfall of around 4%,
much of it predicted for northern areas.
|
|
There are also in the predictions signals for an increase in
winter rainfall and frequency of major storms across the UK. Summer,
however, will see a decrease in rainfall, particularly for southern
parts of Britain.
So, how do we know that climate models produce
credible results?
Three-dimensional models of the climate are verified against
observed changes before being used to make future climate projections.
Three of the main validation techniques are:
- comparison against recent change - observations of climate
from numerous sites around the globe are available from recent
decades (some individual records such as the Central England
Temperature go back several centuries);
- comparison against observed climate variability - the climate
is naturally variable from day to day, month to month, year
to year and over longer timescales. Occasionally this leads
to extremes of temperature or precipitation, so an important
test of a climate model is whether it can credibly reproduce
such variability;
- comparison against past climate - climate models can be used
to simulate climates of the more distant past, such as the last
glacial maximum (the peak of the last Ice Age around 21,000 BC).
Model results are compared to evidence of past change, such
as tree-ring growth or the thickness of sediment layers in core
samples.
The majority of the work done by the Met Office Hadley Centre
is funded by the Department for Environment, Food and Rural Affairs
(Defra). This link between government and Met Office Hadley Centre,
one of the world's leading research bodies for climate change,
is helping prepare the UK for future challenges the weather may
throw at us.
More
about the Met Office Hadley Centre
|
