IPCC: Six graphs that explain how the climate is changing
- 27 Sep 2013, 16:30
- Freya Roberts
After a week spent meticulously agreeing the exact
wording, the Intergovernmental Panel on Climate Change (IPCC) has
just released a summary of the first part of its major report
reviewing the science of climate change.
Known as the '
Summary for Policymakers' (SPM), the
document describes the physical science behind climate change -
whittling down the latest findings about how and why earth's
climate is changing to just 36 pages.
It also makes predictions about how temperatures
and sea levels might change in the future - relative to their
average levels between 1986 and 2005. The two main ones we'll touch
on here are RCP2.6, a low emissions scenario where carbon emissions
are rapidly cut, and RCP8.5, a high emissions scenario with no
But who can be bothered to read a 36 page
document? So here are 6 pictures (okay, graphs…) to give you the
The amount of carbon dioxide in the atmosphere
Measurements show the concentration of carbon
dioxide in the atmosphere has risen. Since pre-industrial times,
carbon dioxide levels have increased 40 per cent. The biggest cause
of the increase is fossil fuel emissions, while land use changes -
for example turning forest into farmland - are the second biggest
The earth's surface is warming:
Between 1880 and 2012, earth's surface has
warmed by approximately 0.85°C. Surface temperatures fluctuate
substantially, and warming has naturally occurred more slowly in
some decades that others, but data collected by a number of
scientific institutions confirms a long term warming
Arctic sea ice is melting:
The amount of ice left at the end of the summer
melt season in the Arctic is shrinking. The area of ice covered
ocean - also known as sea ice extent - has shrunk by between 3.5
and 4.1 per cent per decade since satellite records began in 1979.
The change in summer months has been particularly strong, with ice
extent decreasing 13 per cent per decade.
Earth's surface will continue
The report predicts that surface temperatures
will continue to rise. Depending on the amount of greenhouse gases
produced in the future, temperatures could rise by as little as
0.3°C or as much as 4.8°C. The mean temperature rise predicted
under the IPCC's low emissions scenario (RCP2.6) is 1°C by 2100.
But remember! That's a scenario where we cut emissions
Under a high emissions scenario (RCP8.5) where
emissions continue to grow, 3.7°C of warming is likely.
Sea levels will rise:
Sea levels are predicted to rise as glaciers and
ice sheets melt, and ocean water warms and expands. By the end of
the century, sea levels are likely to rise by between 26 and 82
centimetres (cm). The mean sea level rise predicted under the
IPCC's low emissions scenario is 40cm, while a high emissions
scenario could result in an average of 63cm of sea level
Rainfall patterns will change:
Rainfall patterns are expected to change by the
end of the century, with wet regions getting wetter and dry regions
getting drier (generally speaking). Under a low emissions scenario
this contrast is likely to be less obvious. But under the high
emissions scenarios, some places will receive up to 50 per cent
more rainfall, while others receive up to 30 per cent
There's more to it
These are just a few of the new report's
findings. The extra heat being trapped as a result
of human activities is causing glaciers and ice sheets to melt, the
oceans to warm and expand, it's changing extreme weather events,
leading to hotter hot days fewer cool nights.
How these impacts continue to take effect over
the 21st century very much depends on whether or not greenhouse gas
emissions can be curbed, the report concludes.
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