IPCC Climate Change Report Released

As good a primer on the IPCC and its report as any I suppose. I’m not familiar with Wunderground, but it has devised a good summary. View it here.

UN Climate Panel Endorses Ceiling on Global Emissions – New York Times

STOCKHOLM — The world’s top climate scientists on Friday formally embraced an upper limit on greenhouse gases for the first time, establishing a target level at which humanity must stop spewing them into the atmosphere or face irreversible climatic changes. They warned that the target is likely to be exceeded in a matter of decades unless steps are taken soon to reduce emissions.

Unveiling the latest United Nations assessment of climate science, the experts cited a litany of changes that were already under way, warned that they were likely to accelerate and expressed virtual certainty that human activity is the main cause.

“Climate change is the greatest challenge of our time,” said Thomas F. Stocker, co-chairman of the Intergovernmental Panel on Climate Change, the United Nations-sponsored group of scientists that produced the report. “In short, it threatens our planet, our only home.”

The panel, in issuing its most definitive assessment yet of the risks of human-caused warming, hoped to give impetus to international negotiations toward a new climate treaty, which have languished in recent years in a swamp of technical and political disputes. The group made clear that time was not on the planet’s side if emissions continued unchecked.

From the Guardian:

IPCC Report: Australia can expect 6C Rise on Hottest Days: Reptile, bird and mammal species set to vanish along with Kakadu wetlands by end of century, scientists’ report reveals

To keep average global temperature rises below 2C – the internationally agreed upper limit of warming – greenhouse gas emissions will need to be cut by 10% a year, according to the report.

In a statement released after a laborious process where the IPCC report was trawled over line by line by 110 nations, the UN body said governments had been handed a “firm mandate” to act on climate change.

“The report confirms that the planet is heating up, sea level rise is accelerating, the rate of Arctic Sea ice retreat has doubled, the melting of glaciers and ice sheets is happening faster, and the oceans are acidifying,” it said.

“This report shows that the science on climate change is clear. The debate about who is responsible is over. People rightly demand that governments tackle the climate risk posed to our communities and economies.”

Livescience: IPCC Climate Change Experts React. A  somewhat disingenuous headline, much of the reception reported by Livescience comes from IPCC scientists. Still, a nice smattering of reactions.

Today’s report is the first of four that will make up the IPCC’s Fifth Assessment Report. The remaining parts, which will examine the socioeconomic impacts of climate change and ways to mitigate its effects, will be released in 2014. [See how the 2013 IPCC report compares to previous predictions]

 BBC: 

After a week of intense negotiations in the Swedish capital, the summary for policymakers on the physical science of global warming has finally been released.

The first part of an IPCC trilogy, due over the next 12 months, this dense, 36-page document is considered the most comprehensive statement on our understanding of the mechanics of a warming planet.

It states baldly that, since the 1950s, many of the observed changes in the climate system are “unprecedented over decades to millennia”.

Each of the last three decades has been successively warmer at the Earth’s surface, and warmer than any period since 1850, and probably warmer than any time in the past 1,400 years.

In the summary for policymakers, the scientists say that sea level rise will proceed at a faster rate than we have experienced over the past 40 years. Waters are expected to rise, the document says, by between 26cm (at the low end) and 82cm (at the high end), depending on the greenhouse emissions path this century.

The scientists say ocean warming dominates the increase in energy stored in the climate system, accounting for 90% of energy accumulated between 1971 and 2010.

For the future, the report states that warming is projected to continue under all scenarios. Model simulations indicate that global surface temperature change by the end of the 21st Century is likely to exceed 1.5 degrees Celsius, relative to 1850.

Prof Sir Brian Hoskins, from Imperial College London, told BBC News: “We are performing a very dangerous experiment with our planet, and I don’t want my grandchildren to suffer the consequences of that experiment.”