Washington/Nairobi,
24 September 2009 -The pace and scale of
climate change may now be outstripping even
the most sobering predictions of the last
report of the Intergovernmental Panel of
Climate Change (IPCC).
An analysis of the very
latest, peer-reviewed science indicates
that many predictions at the upper end of
the IPCC's forecasts are becoming ever more
likely.
Meanwhile, the newly
emerging science points to some events thought
likely to occur in longer-term time horizons,
as already happening or set to happen far
sooner than had previously been thought.
Researchers have become
increasingly concerned about ocean acidification
linked with the absorption of carbon dioxide
in seawater and the impact on shellfish
and coral reefs.
? Water that can corrode
a shell-making substance called aragonite
is already welling up along the California
coast?decades earlier than existing models
predict.
Losses from glaciers,
ice-sheets and the Polar Regions appear
to be happening faster than anticipated,
with the Greenland ice sheet, for example,
recently seeing melting some 60 percent
higher than the previous record of 1998.
? Some scientists are
now warning that sea levels could rise by
up to two metres by 2100 and five to ten
times that over following centuries.
There is also growing
concern among some scientists that thresholds
or tipping points may now be reached in
a matter of years or a few decades including
dramatic changes to the Indian sub-continent's
monsoon, the Sahara and West Africa monsoons,
and climate systems affecting a critical
ecosystem like the Amazon rainforest.
The report also underlines
concern by scientists that the planet is
now committed to some damaging and irreversible
impacts as a result of the greenhouse gases
already in the atmosphere.
? Losses of tropical
and temperate mountain glaciers affecting
perhaps 20 percent to 25 percent of the
human population in terms of drinking water,
irrigation and hydro-power.
? Shifts in the hydrological
cycle resulting in the disappearance of
regional climates with related losses of
ecosystems, species and the spread of drylands
northwards and southwards away from the
equator.
Recent science suggests
that it may still be possible to avoid the
most catastrophic impacts of climate change.
However, this will only happen if there
is immediate, cohesive and decisive action
to both cut emissions and assist vulnerable
countries adapt.
These are among the
findings of a report released today by the
United Nations Environment Programme (UNEP)
entitled Climate Change Science Compendium
2009.
The report, compiled
in association with scientists around the
world, comes with less than 80 days to go
to the crucial UN climate convention meeting
in Copenhagen, Denmark.
In a foreword to the
document, the United Nations Secretary-General,
Ban Ki-moon, who this week hosted heads
of state in New York, writes, "This
Climate Change Science Compendium is a wake-up
call. The time for hesitation is over".
"We need the world
to realize, once and for all, that the time
to act is now and we must work together
to address this monumental challenge. This
is the moral challenge of our generation."
The Compendium reviews
some 400 major scientific contributions
to our understanding of Earth Systems and
climate change that have been released through
peer-reviewed literature, or from research
institutions, over the last three years.
Achim Steiner, UN Under-Secretary
General and UNEP Executive Director, said,
"The Compendium can never replace the
painstaking rigour of an IPCC process?a
shining example of how the United Nations
can provide a path to consensus among the
sometimes differing views of more than 190
nations".
"However, scientific
knowledge on climate change and forecasting
of the likely impacts has been advancing
rapidly since the landmark 2007 IPCC report,"
he added.
"Many governments
have asked to be kept abreast of the latest
findings. I am sure that this report fulfils
that request and will inform ministers'
decisions when they meet in the Danish capital
in only a few weeks time," said Mr.
Steiner.
The research findings
and observations in the Compendium are divided
into five categories: Earth Systems, Ice,
Oceans, Ecosystems and Management. Key developments
documented since the IPCC Fourth Assessment
Report include:
Earth Systems
? A new climate modeling
system, forecasting average temperatures
over a decade by combining natural variation
with the impacts of human-induced climate
change, projects that at least half of the
10 years following 2009 will exceed the
warmest year currently on record. This is
despite the fact that natural variation
will partially offset the warming "signal"
from greenhouse gas emissions.
? The growth in carbon
dioxide emissions from energy and industry
has exceeded even the most fossil-fuel intensive
scenario developed by the IPCC at the end
of the 11000s. Global emissions were growing
by 1.1 percent each year from 11000-1999
and this accelerated to 3.5 percent per
year from 2000-2007.
? The developing and
least-developed economies, 80 percent of
the world's population, accounted for 73
percent of the global growth of emissions
in 2004. However, they contributed only
41 percent of total emissions, and just
23 percent of cumulative emissions since
10000.
? Growth of the global
economy in the early 2000s and an increase
in its carbon intensity (emissions per unit
of growth), combined with a decrease in
the capacity of ecosystems on land and the
oceans to act as carbon "sinks",
have led to a rapid increase in the concentrations
of carbon dioxide in the atmosphere. This
has contributed to sooner-than-expected
impacts including faster sea-level rise,
ocean acidification, melting Arctic sea
ice, warming of polar land masses, freshening
of ocean currents and shifts in the circulation
patterns of the oceans and atmosphere.
? The observed increase
in greenhouse gas concentrations are raising
concern among some scientists that warming
of between 1.4 and 4.3 degrees Centigrade
above pre-industrial surface temperatures
could occur. This exceeds the range of between
1 and 3 degrees perceived as the threshold
for many "tipping points", including
the end of summer Arctic sea ice, and the
eventual melting of Himalayan glaciers and
the Greenland ice sheet.
Ice
? The melting of mountain
glaciers appears to be accelerating, threatening
the livelihoods of one fifth or more of
the population who depend on glacier ice
and seasonal snow for their water supply.
For 30 reference glaciers in nine mountain
ranges tracked by the World Glacier Monitoring
Service, the mean rate of loss since 2000
has roughly doubled since the rate during
the previous two decades. Current trends
suggest that most glaciers will disappear
from the Pyrenees by 2050 and from the mountains
of tropical Africa by 2030.
? In 2007, summer sea
ice in the Arctic Ocean shrank to its smallest
extent ever, 24 percent less than the previous
record in 2005, and 34 percent less than
the average minimum extent in the period
1970-2000. In 2008, the minimum ice extent
was 9 percent greater than in 2007, but
still the second lowest on record.
? Until the summer of
2007, most models projected an ice-free
September for the Arctic Ocean towards the
end of the current century. Reconsideration
based on current trends has led to speculation
that this could occur as soon as 2030.
? Melting of the Greenland
Ice Sheet surface also seems to be accelerating.
In the summer of 2007, the rate of melting
was some 60 percent higher than the previous
record in 1998.
? The loss of ice from
West Antarctica is estimated to have increased
by 60 per cent in the decade to 2006, and
by 140 percent from the Antarctic Peninsula
in the same period.
? Recent findings show
that warming extends well to the south of
the Antarctic Peninsula, to cover most of
West Antarctica, an area of warming much
larger than previously reported.
? The hole in the ozone
layer has had a cooling effect on Antarctica,
and is partly responsible for masking expected
warming on the continent. Recovery of stratospheric
ozone, thanks to the phasing out of ozone-depleting
substances, is projected to increase Antarctic
temperatures in coming decades.
Oceans
? Recent estimates of
the combined impact of melting land-ice
and thermal expansion of the oceans suggest
a plausible average sea level rise of between
0.8 and 2.0 metres above the 11000 level
by 2100. This compares with a projected
rise of between 18 and 59 centimetres in
the last IPCC report, which did not include
an estimate of large-scale changes in ice-melt
rates, due to lack of consensus.
? Oceans are becoming
more acidic more quickly than expected,
jeopardizing the ability of shellfish and
corals to form their external skeletons.
Water that can corrode a shell-making carbonate
substance called aragonite is already welling
up during the summer along the California
coast, decades earlier than models predict.
Ecosystems
? Since the 2007 IPCC
report, wide-ranging surveys have shown
changes to the seasonal behaviour and distribution
of all well-studied marine, freshwater and
terrestrial groups of plants and animals.
Polar and mountaintop species have seen
severe contractions of their ranges.
? A recent study projecting
the impacts of climate change on the pattern
of marine biodiversity suggests dramatic
changes to come. Ecosystems in sub-polar
waters, the tropics and semi-enclosed seas
are predicted to suffer numerous extinctions
by 2050, while the Arctic and Southern Oceans
will experience severe species invasions.
Marine ecosystems as a whole may see a species
turnover of up to 60 percent.
? Under the IPCC scenario
that most closely matches current trends
? i.e. with the highest projected emissions
? between 12 and 39 percent of the Earth's
land surface could experience previously
unknown climate conditions by 2100. A similar
proportion, between 10 and 48 percent, will
see existing climates disappear. Many of
these "disappearing climates"
coincide with biodiversity hotspots, and
with the added problem of fragmented habitats
and physical obstructions to migration,
it is feared many species will struggle
to adapt to the new conditions.
? Perennial drought
conditions have already been observed in
South-eastern Australia and South-western
North America. Projections suggest that
persistent water scarcity will increase
in a number of regions in coming years,
including southern and northern Africa,
the Mediterranean, much of the Middle East,
a broad band in Central Asia and the Indian
subcontinent.
Management
? The reality of a rapidly-changing
climate may make conventional approaches
to conservation and restoration of habitats
ineffective. Drastic measures such as large-scale
translocation or assisted colonization of
species may need to be considered.
? Eco-agriculture, in
which landscapes are managed to sustain
a range of ecosystem services, including
food production, may need to replace the
current segregation of land use between
conservation and production. This could
help create resilient agricultural ecosystems
better able to adapt to the changing climate
conditions.
? Experts increasingly
agree that active protection of tropical
forests is a cost-effective means of cutting
global emissions. An international mechanism
of reducing emissions from deforestation
and forest degradation (REDD) is likely
to emerge as a central component of a new
agreement in Copenhagen. However, many issues
need to be resolved, such as how to verify
the reductions and ensuring fair treatment
of local and indigenous forest communities.
? A number of innovative
approaches are emerging to keep carbon out
of the atmosphere, including the use of
"biochar", biologically-derived
charcoal. It is mixed in soils, increasing
fertility and potentially locking up carbon
for centuries. This is a 21st century application
of a technology known as Terra Preta, or
Black Earth, used by Amazon peoples before
the arrival of Europeans in South America.
To download the full report, visit http://www.unep.org/compendium2009/
For more information please contact:
Nick Nuttall, UNEP Spokesperson and Head
of MediaElisabeth Guilbaud-Cox, Senior Communications
Officer, UNEP Regional Office for North
America
