Climate impacts 'overwhelming' - UN

http://www.bbc.com/news/science-environment-26810559



The impacts of global warming are likely to be "severe, pervasive and irreversible", a major report by the UN has warned.

Scientists and officials meeting in Japan say the document is the most comprehensive assessment to date of the impacts of climate change on the world.

Some impacts of climate change include a higher risk of flooding and changes to crop yields and water availability.

Humans may be able to adapt to some of these changes, but only within limits.

An example of an adaptation strategy would be the construction of sea walls and levees to protect against flooding. Another might be introducing more efficient irrigation for farmers in areas where water is scarce.

Natural systems are currently bearing the brunt of climatic changes, but a growing impact on humans is feared.

Members of the UN's climate panel say it provides overwhelming evidence of the scale of these effects.

Our health, homes, food and safety are all likely to be threatened by rising temperatures, the summary says.

The report was agreed after almost a week of intense discussions here in Yokohama, which included concerns among some authors about the tone of the evolving document.

This is the second of a series from the Intergovernmental Panel on Climate Change (IPCC) due out this year that outlines the causes, effects and solutions to global warming.

This latest Summary for Policymakers document highlights the fact that the amount of scientific evidence on the impacts of warming has almost doubled since the last report in 2007.

Be it the melting of glaciers or warming of permafrost, the summary highlights the fact that on all continents and across the oceans, changes in the climate have caused impacts on natural and human systems in recent decades.

In the words of the report, "increasing magnitudes of warming increase the likelihood of severe, pervasive and irreversible impacts".

"Nobody on this planet is going to be untouched by the impacts of climate change,'' IPCC chairman Rajendra Pachauri told journalists at a news conference in Yokohama.

Dr Saleemul Huq, a convening lead author on one of the chapters, commented: "Before this we thought we knew this was happening, but now we have overwhelming evidence that it is happening and it is real."

Michel Jarraud, secretary-general of the World Meteorological Organization, said that, previously, people could have damaged the Earth's climate out of "ignorance".

"Now, ignorance is no longer a good excuse," he said.

Mr Jarraud said the report was based on more than 12,000 peer-reviewed scientific studies. He said this document was "the most solid evidence you can get in any scientific discipline".

US Secretary of State John Kerry commented: "Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy. Denial of the science is malpractice."

He added: "No single country causes climate change, and no one country can stop it. But we need to match the urgency of our response with the scale of the science."

Ed Davey, the UK Energy and Climate Secretary said: "The science has clearly spoken. Left unchecked, climate change will impact on many aspects of our society, with far reaching consequences to human health, global food security and economic development.

"The recent flooding in the UK is a testament to the devastation that climate change could bring to our daily lives."

The report details significant short-term impacts on natural systems in the next 20 to 30 years. It details five reasons for concern that would likely increase as a result of the warming the world is already committed to.

These include threats to unique systems such as Arctic sea ice and coral reefs, where risks are said to increase to "very high" with a 2C rise in temperatures.

The summary document outlines impacts on the seas and on freshwater systems as well. The oceans will become more acidic, threatening coral and the many species that they harbour.

On land, animals, plants and other species will begin to move towards higher ground or towards the poles as the mercury rises.

Humans, though, are also increasingly affected as the century goes on.

Food security is highlighted as an area of significant concern. Crop yields for maize, rice and wheat are all hit in the period up to 2050, with around a tenth of projections showing losses over 25%.

After 2050, the risk of more severe yield impacts increases, as boom-and-bust cycles affect many regions. All the while, the demand for food from a population estimated to be around nine billion will rise.

Many fish species, a critical food source for many, will also move because of warmer waters.

In some parts of the tropics and in Antarctica, potential catches could decline by more than 50%.

"This is a sobering assessment," said Prof Neil Adger from the University of Exeter, another IPCC author.

"Going into the future, the risks only increase, and these are about people, the impacts on crops, on the availability of water and particularly, the extreme events on people's lives and livelihoods."

People will be affected by flooding and heat related mortality. The report warns of new risks including the threat to those who work outside, such as farmers and construction workers. There are concerns raised over migration linked to climate change, as well as conflict and national security.

Report co-author Maggie Opondo of the University of Nairobi said that in places such as Africa, climate change and extreme events mean "people are going to become more vulnerable to sinking deeper into poverty".

While the poorer countries are likely to suffer more in the short term, the rich won't escape.

"The rich are going to have to think about climate change. We're seeing that in the UK, with the floods we had a few months ago, and the storms we had in the US and the drought in California," said Dr Huq.

"These are multibillion dollar events that the rich are going to have to pay for, and there's a limit to what they can pay."

But it is not all bad news, as the co-chair of the working group that drew up the report points out.

"I think the really big breakthrough in this report is the new idea of thinking about managing climate change as a problem in managing risks," said Dr Chris Field.

"Climate change is really important but we have a lot of the tools for dealing effectively with it - we just need to be smart about it."

There is far greater emphasis to adapting to the impacts of climate in this new summary. The problem, as ever, is who foots the bill?

"It is not up to IPCC to define that," said Dr Jose Marengo, a Brazilian government official who attended the talks.

"It provides the scientific basis to say this is the bill, somebody has to pay, and with the scientific grounds it is relatively easier now to go to the climate negotiations in the UNFCCC (United Nations Framework Convention on Climate Change) and start making deals about who will pay for adaptation."

http://www.bbc.com/news/science-environment-26810559

 

Are there still deniers of this?

http://www.cnn.com/2014/03/30/world/un-climate-report/index.html?hpt=hp_inthenews

Little time left to turn down the world's heat, U.N. says

(CNN) -- Your forecast for the next century: Hotter, drier and hungrier, and the chance to turn down the thermostat is slipping away.
That's the latest conclusion from the United Nations, which urged governments to address the "increasingly clear" threats posed by a warming climate before some options are closed off for good. The latest report from the Intergovernmental Panel on Climate Change concluded that taking steps to reduce the carbon dioxide emissions blamed for rising temperatures could buy more time to adjust to a warmer world.

Cutting emissions now "increases the time available for adaptation to a particular level of climate change," the report states. But it adds, "Delaying mitigation actions may reduce options for climate-resilient pathways in the future."

"In many cases, we are not prepared for the climate-related risks that we already face," Vicente Barros, the co-chaiman of the IPCC working group behind the document, said in a statement accompanying the report. "Investments in better preparation can pay dividends both for the present and for the future."

U.N. climate report: Time running out The soaring cost of climate change Climate change is not debatable
The summary for policymakers was released Monday morning in Yokohama, Japan. It's the second part of the IPCC's benchmark assessment of climate change, a document released every six years with the input of nearly 1,000 scientists. Without checks on emissions, the impacts of climate change will be more severe, more likely, and possibly irreversible, it concludes.

Monday's report underscores "that we have committed to a certain amount of warming," said Kelly Levin, an energy and climate expert at the U.S.-based World Resources Institute.

"Over the next few decades, we are going to lock ourselves into a climate change commitment that is going to paint a very different world, depending on what we choose today," Levin said. "The choices we make today are going to affect the risks we face through the rest of the century."
As a result, "Adaptation is emerging as central area in climate change research," Levin said. But adaptation -- steps such as building sea walls, conserving water and designing cities for warmer climates -- has its limits, she said.

"The report suggests some options are going to be too resource-intensive or too expensive," she said.

An increase in atmospheric carbon dioxide and other emissions have driven average temperatures up by about 0.6 degrees Celsius (1 degree Fahrenheit) since 1950, the IPCC says. The first part of its report, released in September, concluded that even a best-case scenario would result in an increase in global average temperatures of 1.6 C; the worst-case scenario estimates a rise of 3.7 degrees Celsius (6.6 Fahrenheit).
The idea that carbon emissions are changing the Earth's climate is politically controversial, but generally accepted as fact by the overwhelming majority of scientists. And as emissions continue to rise, driving up CO2 concentrations in the atmosphere, the impacts will be more severe, more likely and possibly irreversible, Monday's report states.

The summary of the full document -- which is more than 1,000 pages -- will be the premiere guide for lawmakers. It breaks down the expected impacts by continent and by categories such as marine life, agriculture and flood risks. And by diving into the specifics of the report, policymakers will be able to see what risks their specific locations face, as well as what adaptation and mitigation techniques could prove fruitful.
"The real highlight is how many impacts there are, how widespread they are and how pervasive they are around the world," said Heather McGray, who studies adaptation at WRI.

In most cases, climate change will exacerbate existing problems, such as the availability of fresh water in sub-Saharan Africa. The authors conclude that glaciers will continue to shrink "almost worldwide," affecting water supplies downstream.
Animals have begun shifting their habitats in response to a warming world, and key crops have been affected already, they wrote. Colder climates may see increases in crop yields from longer growing seasons and milder temperatures, but the negative effects are expected to outweigh the positive, the report states.

"In this report, the finding is the impacts of climate change are already widespread and consequential," McGray said.
The impacts won't be the same for everyone, and as usual, the world's poor are more likely to be hurt.

"Climate-related hazards affect poor people's lives directly through impacts on livelihoods, reductions in crop yields or destruction of homes and indirectly through, for example, increased food prices and food insecurity," the report states. Positive effects on the impoverished "are limited and often indirect."

For those people, the effects "will be catastrophic" unless emissions can be reduced, McGray said.

 

Texx, does this mean you are no longer doubting man made climate change? Have you accepted it as fact?

 

So, 97% of the scientists in the world are wrong about this?