UN Review of Recent Climate Research Concludes That Impacts Of Climate Change Coming Faster Than Anticipated
25 September 2009
|Significant climate anomalies 2008/2009. Source: Climate Change Compendium. Click to enlarge.|
A UN review of some 400 major scientific contributions to Earth systems and climate science released through peer-reviewed literature or from research institutions over the last three years, has found that the pace and scale of climate change may now be outstripping even the worst case predictions of the last report of the Intergovernmental Panel of Climate Change (IPCC). (Earlier post.)
The report released by the United Nations Environment Programme (UNEP), entitled Climate Change Science Compendium 2009, highlights new research that identifies 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.
Ocean acidification caused by the absorption of carbon dioxide in seawater is already increasing 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% higher than the previous record of 1998.
Some scientists are now warning that sea levels could rise by up to two meters 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 significant 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 20-25% 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.
The research findings and observations in the Compendium are divided into five categories: Earth Systems, Ice, Oceans, Ecosystems and Systems Management. Key developments documented since the IPCC Fourth Assessment Report include:
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 1990s. Global emissions were growing by 1.1% each year from 1990-1999 and this accelerated to 3.5% per year from 2000-2007.
The developing and least-developed economies, 80% of the world’s population, accounted for 73% of the global growth of emissions in 2004. However, they contributed only 41% of total emissions, and 23% of cumulative emissions since 1750.
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.
...with estimations of 1-5 degrees Celsius as the range of GMT increase over 1750 levels as the threshold for tipping elements and 0-5 degrees Celsius over 1990 levels as reasons for concern, some researchers are realizing that we have already committed ourselves to significant environmental changes. The observed increase in GHG concentration since 1750 has most likely committed the world to a warming of 1.4-4.3 degrees Celsius, above pre-industrial surface temperatures. The equilibrium warming above pre-industrial temperatures that the world will observe is 2.4 degrees Celsius—even if GHG concentrations had been fixed at their 2005 concentration levels and without any other anthropogenic forcing such as the cooling effect of aerosols.
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% less than the previous record in 2005, and 34% less than the average minimum extent in the period 1970-2000. In 2008, the minimum ice extent was 9% 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% higher than the previous record in 1998.
The loss of ice from West Antarctica is estimated to have increased by 60% in the decade to 2006, and by 140% 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.
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 meters above the 1990 level by 2100. This compares with a projected rise of between 18 and 59 centimeters 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.
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%.
Under the IPCC scenario that most closely matches current trends—i.e. with the highest projected emissions—between 12 and 39% of the Earth’s land surface could experience previously unknown climate conditions by 2100. A similar proportion, between 10 and 48%, 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.
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.
This should be bookmarked for future reference. Some of the chart events - highest Canadian snowfall:lowest Arctic ice.. seem inconsistent.
Posted by: kelly | 25 September 2009 at 05:53 AM
Not really. Warmer air holds more moisture, thus the heaviest snowfalls occur when the air temp is just below 0'C. That's not cold enough to freeze seawater.
It may now be too late to save places like New Orleans, South Florida, Bangladesh, the Netherlands, and Shanghai.
Posted by: richard schumacher | 25 September 2009 at 07:28 AM
Increased desertification will also come with increased temperatures. This is already happening in north-west Agentina, China, India, Australia, southern parts of ex-USSR, Africa, other south American countries etc.
Food production could come down by up to 1%/year in the affected areas. Considering that the global population may reach 9+ billions before 2100, grain ethanol and other biofuel productions may have to be curtailed in favour of food production.
Maldives Islands may be among the fisrt land mass to go. The Netherlands may have to raise their dikes another 5 m.? They could do it over a few decades.
Posted by: HarveyD | 25 September 2009 at 09:41 AM
The earth is acting as a classic chaotic system, where inputs have amplifying outputs. It's a non-linear world. Unfortunately, politicans and business live in a linear one.
Posted by: fred schumacher | 25 September 2009 at 10:16 AM
Big F*ing surprise.
During the 8 year of the Bush misadministration, they where able to water down the IPCC reports.
Posted by: dursun | 25 September 2009 at 10:46 AM
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.
I've never understood the logic here. If something is happening 'decades earlier' than your model predicts, it doesn't mean that things are getting worse faster, it means your model is WRONG. Go away, and don't come back until you get it right.
Posted by: Matthew | 25 September 2009 at 11:57 AM
"it means your model is WRONG."
Or the model is right and the external parameters that drive the model are changing faster than assumed.
For instance, there's model for how fast the Moon orbit the Earth. Of you don't enter in the correct masses, you get a wrong answer, but the model is fine.
House Committee on Oversight and Government Reform
Posted by: dursun | 25 September 2009 at 01:45 PM
Yes, modeling the real world isn't simple. Take medicine for example. Even with all our undersanding of pysiology it's hard to predict exactly how fast a cancer might progress or how it will respond to a particular medicine... and yet those silly doctors think we should appreciate their woefully incomplete knowledge. Of course after the patient is dead, they can predict with a high degree of accuracy.
So by all means... scientists need to just shut up... don't come back until you can say with certainty that every last shellfish is dead. No inaccuracy will be accepted.
Posted by: RhapsodyInGlue | 25 September 2009 at 06:12 PM
What do AGW deniers consider to be sufficient evidence? When Greenland's half melted?
Posted by: Mark_BC | 25 September 2009 at 06:45 PM
Dursun - Which external parameter do you suppose might be changing faster than assumed? We've got pretty good measurements of all the greenhouse gasses, after all. Influences from the sun? Possibly, but we've been assured it's pure craziness to think the sun has anything to do with temperatures down here.
Rhapsody - Medical models are accepted because, for the most part, they work for most patients. Unlike medical studies with hundreds or thousands of patients, we have only one Earth - so if you're going to claim to model it, you have to get it pretty close to right. Being 'decades' off in a prediction doesn't mean you're close, it means you're wrong. There's no shame in that, just go back and figure out why you got it wrong and try again. When you have a model that isn't obviously defective, people might listen to what you and your model have to say.
Posted by: Matthew | 25 September 2009 at 07:14 PM
"Unlike medical studies with hundreds or thousands of patients, we have only one Earth"
Which means, err on the side of caution because you don't get a second chance. Especially when there are many positive economic, social, and related environmental benefits associated with reducing GHG emissions.
"When you have a model that isn't obviously defective, people might listen to what you and your model have to say."
When Greenland's gone? Isn't that too late?
Posted by: Mark_BC | 25 September 2009 at 09:01 PM
"Dursun - Which external parameter do you suppose might be changing faster than assumed?"
I'm not a climatologist, I wouldn't presume to be able to critique some 400 major scientific contributions to Earth systems and climate science released through peer-reviewed literature or from research institutions over the last three years,
Perhaps you feel qualified?
Posted by: dursun | 25 September 2009 at 09:49 PM
Dursun - So why have a brain of your own, if you're just going to blindly accept what other people tell you? Think for yourself, it can be refreshing.
Posted by: Matthew | 26 September 2009 at 06:24 AM
"We are sinking, say Maldive islanders, but there is still time to save the world." http://www.timesonline.co.uk/tol/news/environment/article6845261.ece
These guys believe GHG emissions yield global warming. You might say they are waist deep in their beliefs and have some property to sell all those who don't believe them.
Posted by: kelly | 26 September 2009 at 06:41 AM
Sea level has been rising for a hundred or more years. What did the islanders believe before Al Gore told them it was our fault? Maybe we should offer some virgin sacrifices to the local gods; obeying them makes just as much sense as obeying broken computer models.
Posted by: Matthew | 26 September 2009 at 07:05 AM
So why have a brain of your own, if you're just going to blindly accept what other people tell you? Think for yourself, it can be refreshing.
This is rich, especially when you consider most of the AGW deniers are republicans who blindly accepted what Bush told them about Saddam and 9/11, and yellow cake from Affica.
BTW Yes sea level has risen in the past but before AGW it happen slowly enough that the corals that surround the Maldive islands could keep up. The Maldive islands are a group of atolls.
"Darwin explained the creation of coral atolls in the South Pacific (1842) based upon observations made during a five-year voyage aboard the HMS Beagle (1831–1836). His explanation, which is accepted as basically correct, involved considering that several tropical island types—from high volcanic island, through barrier reef island, to atoll—represented a sequence of gradual subsidence of what started as an oceanic volcano. He reasoned that a fringing coral reef surrounding a volcanic island in the tropical sea will grow upwards as the island subsides (sinks), becoming an "almost atoll" (barrier reef island) (as typified by an island such as Aitutaki in the Cook Islands, Bora Bora and others in the Society Islands). The fringing reef becomes a barrier reef for the reason that the outer part of the reef maintains itself near sea level through biotic growth, while the inner part of the reef falls behind, becoming a lagoon because conditions are less favorable for the corals and calcareous algae responsible for most reef growth. In time, subsidence carries the old volcano below the ocean surface, but the barrier reef remains. At this point, the island has become an atoll.
Atolls are the product of the growth of tropical marine organisms, so these islands are only found in warm tropical waters. Volcanic islands located beyond the warm water temperature requirements of reef building (hermatypic) organisms become seamounts as they subside and are eroded away at the surface. An island that is located where the ocean water temperatures are just sufficiently warm for upward reef growth to keep pace with the rate of subsidence is said to be at the Darwin Point. Islands more polar evolve towards seamounts or guyots; islands more equatorial evolve towards atolls."
Posted by: ai_vin | 26 September 2009 at 08:22 AM
It's obvious Matt that you're not in the Reality Based Community.
You can judge for yourself what is True without the encumbrance of Reality.
Posted by: dursun | 26 September 2009 at 08:37 AM
Dursun - Let me get this straight...you're blindly following the pronouncements of men in white coats who can't build a working model, but *I* am reality-challenged?
Posted by: Matthew | 26 September 2009 at 10:24 AM
It's pretty hard to build a "Working Model" of the earth.
For one thing, you don't have anyplace to stand ...
Posted by: Lucas | 26 September 2009 at 05:27 PM
Matthew: How accurate would the models have to be in order for you feel that caution was in order?
Also: "we've been assured it's pure craziness to think the sun has anything to do with temperatures down here."
By whom have you need assured that? All the models I've read about include solar forcing... in fact solar forcing is pretty much the starting point of any climate system model. Or am I missing something?
Posted by: Nat Pearre | 28 September 2009 at 03:03 PM
Nat - At a minimum, I would expect a useful model to accurately 'predict' current conditions. A model that predicts acidic upwellings in 2040 that are occurring now is not sufficiently accurate.
As for solar forcings...sure, the models all incorporate the usual Total Solar Irradiance (TSI) measure. Problem is, we're learning that there's a lot more to the Earth-Sun interaction than what's included in TSI. Magnetic coupling, cosmic ray modulation, you name it...there's a lot we're just starting to figure out. But mention the sun to an AGW true believer, and all you'll get back is that the 1366 watts/square meter figure hasn't fluctuated by more than some tiny amount, and therefore the sun has nothing to do with changes here on Earth.
For extra fun, remind them that the rest of the solar system appears to be experiencing global warming as well, and watch them really start to scream.
Posted by: Matthew | 29 September 2009 at 12:06 PM
There's a limit to human ability to accurately measure the conditions that factor into AGW. There's a limitation on our understanding of how certain subsystems work. Factor in the fact that climate in based on chaos math, in which small permutations cause large shifts and you can see that complete accuracy of something like the climate is an impossibility.
What should be noted is that the trends predicted are basically coming true, showing that the general conceptualizations of whats happening are based on reality.
This should be a call to expedite our efforts. Either we've overestimated the negative feedback mechanisms holding things back, or we've underestimated the positive feedback mechanisms. A huge underestimation was the artic permafrost.
If you're in a speeding car and heading for a collision, you've just modelled wrong. You don't argue about the model, you try to avoid the collision immediately. The costs of climate change are well documented and have global scope and we're colliding with them very obviously.
Posted by: aym | 03 October 2009 at 10:28 AM