UN report to point to mounting climate challenge

Scientists will hike pressure next week on the UN's troubled climate talks as they release a report pointing to the dizzying challenge of meeting the international body's target for global warming.

In the first volume of a massive trilogy, the Nobel-winning Intergovernmental Panel on Climate Change (IPCC) will publish its projections for warming by 2100.

Just a single scenario—and by far the toughest to achieve—sees the possibility of safely anchoring the to within two degrees Celsius (3.6 degrees Fahrenheit), according to a draft seen by AFP.

In the other projections, the UN's much-trumpeted 2 C goal will be overshot.

At the very top of the range, warming would be more than double the UN target and more than triple that set by vulnerable small-island states.

Warming on this scale would gravely accentuate the peril from drought, flood, storms and rising seas.

"It's been known for a long time that we are running out of time," said Alden Meyer, with the US the Union of Concerned Scientists (UCS).

"The longer you wait, the more difficult it becomes and the more expensive it gets."

The UN's panel of has issued only four overviews in 25 years. The last was in 2007 and despite fierce opposition from skeptics, has made many advances since then.

The work released in Stockholm on Friday comprises a 2,000-page report authored by 257 scientists, plus a 31-page Summary for Policymakers.

Over the four preceding days, the summary will be vetted line by line by government representatives from 195 countries. Governments have a seat on the panel but are not allowed to censor the scientists' main report.

The draft document strengthens the IPCC's conviction in 2007—from 90 to 95 percent—that humans are to blame for .

It also sees four projections based on "radiative forcing," or the heat delivered to Earth's surface as a result of fossil-fuel gases and other that trap solar heat.

The lowest scenario sees an average temperature rise of 1.0 C (1.8 F) by 2100, ranging from 0.3 to 1.7 C (0.5-3.1 F).

The highest scenario has an average of 3.7 C (6.7 F), ranging from 2.6 C (4.7 F) to a whopping 4.8 C (8.6 F).

But around 0.8 C (1.4 F) must be added to all these figures to factor in warming since the start of the Industrial Revolution—the yardstick used in the UN target.

Previous research into the lowest scenario says global carbon dioxide (CO2) emissions, currently scaling new highs, must peak by around 2020 and then decline sharply.

By the end of the century, emissions would even have to be negative compared with 2000, say some models.

In other words, some CO2 would have to be stripped out of the atmosphere to help the cooling—something that has no precedent in recent human history.

True to tradition, the IPCC is mute on recommendations and what could be considered a safe maximum, although it cautions that reaching 2C will require "substantially lower" emissions.

Small island states that fear being drowned by rising seas are clamouring for an even more stringent target, of 1.5 C (2.7 F).

Climate's rise and fall as political issue

The IPCC co-won the Nobel Peace Prize after publishing its landmark Fourth Assessment Report, or AR4, in 2007.

After that, climate change as an issue went into decline after the near-fiasco of the 2009 Copenhagen Summit. And the IPCC's own reputation was dented by several mistakes that emerged in AR4.

Together, this enabled climate skeptics to assault the point of curbing greenhouse gases, especially as the world financial crisis began to grip rich economies.

Environmentalists, though, say climate change is a fact that cannot be ducked, and the IPCC is essential for addressing it as its work carries the imprimatur of governments.

"The IPCC is the foundation stone on which the whole of the climate movement is built and on which the whole of climate policy is founded," said Tim Nuthall of the European Climate Foundation.

"It will become the new playbook, just as AR4 did over time... if you take a step back, the report over the next few years will permeate down to so many sections of the economy and society."

Dealing with the greenhouse effect is a political nightmare, touching on high costs and powerful interests.

It entails weaning today's economies off their dependence on coal, oil and gas, the bedrock of their energy supply.

Efforts for a UN pact stumbled in Copenhagen in 2009. The next deadline is for 2015—and even this is beginning to look shaky.

"Greenhouse gases are altering Earth's climate. No serious politician on the planet can now dispute that," the science journal Nature said in an editorial on Wednesday.

But it added: "The governments of the world, to whom the IPCC reports, have made precious little headway in reducing emissions. And they appear in little hurry to do so."

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© 2013 AFP

Citation: UN report to point to mounting climate challenge (2013, September 21) retrieved 18 August 2019 from https://phys.org/news/2013-09-mounting-climate.html
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Sep 21, 2013
"Greenhouse gases are altering Earth's climate. No serious politician on the planet can now dispute that"

Australia's new prime minister, Tony Abbott, is unfortunately not a serious politician... we're going back in time about a decade a day since he came into power.

Sep 21, 2013
"It's been known for a long time that we are running out of time," ..."The longer you wait, the more difficult it becomes and the more expensive it gets."
Waiting seems to be working so far...

Consensus definition of global warming:

"global warming
An increase in the average temperature of the earth's atmosphere, especially a sustained increase sufficient to cause climatic change."

Global temperatures: http://www.woodfo....6/trend

Sep 21, 2013
Temperature is a meter made of devil's cane. Only fools walk upon it.
Verily, what would be required to raise the temperature of the Earth in a meaningful way?
It confounds the educated mind to answer the question. The Earth is not a pot of water over the campfire. Adding heat to it does not provoke a linear, indeed, not even necessarily positive response.
Water shows us how the Earth changes, the recession of the mightly and blessed avatar of water; ice.
The benificant ice saving us from the folly of our fissil fuel expendatures.
The benificent vapor distributing and venting our folly more rapidly!
Blessed is the Water and its many properties, aspects and avatars!

Sep 24, 2013
Scientists will hike pressure next week on the UN's troubled climate talks

I thought they would be trying to figure out how to explain the 17 years of no increase in temperature, the failure of all their models, the increased sea ice, and all the other failed predictions of doom....

The religion of AGW is strong in the UN. High Profit Al Gore needs more indulgences sent his way so he and the AGW elite can fly his private CO2 spewing jet, drive his multitude of private CO2 spewing luxury monster vehicles, and live in his many private CO2 spewing mega mansions. Meanwhile his minions need to live in 1 room apartments lit by a single LED, heated (forget heated spews too much CO2) eating worms recycling their wastes.

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