A UN panel of scientists has used the strongest words yet in its assessment of the state of the world's climate. In a summary of the report published in Stockholm on September 27, the Intergovernmental Panel on Climate Change (IPCC) has raised the probability of most global warming being man-made to 95 percent -- up from 90 percent in its previous report in 2007.
RFE/RL correspondent Antoine Blua spoke to Samantha Smith, leader of the WWF conservation group's Global Climate and Energy Initiative, to tell us more.
RFE/RL: What are the main findings of the report issued [on September 27, 2013] by the Intergovernmental Panel on Climate Change?
Scientists are even more certain that human activity is the main cause of the climate impacts that we have seen over the last 60 years, and those include temperature increases. For example, the last three decades have been each one warmer than the last, and the three warmest decades since preindustrial climate.
RFE/RL: What are the main causes of global warming?
The main cause now is the burning of fossil fuel, there is no doubt about that. And this is also something that the scientists have confirmed. It's human activity and now overwhelmingly the amount of fossil fuel that we are burning and the pollution that is released from that. That would be coal, oil, and gas.
RFE/RL: What does the report says about the oceans?
Oceans are absorbing more than 90 percent of the extra energy or heat that is generated by climate change, so they are warming up. In addition, oceans are absorbing [carbon dioxide] and so the oceans are becoming much more acidic, which is very bad news for coral reefs, fish, and of course the 1 billion -- more or less -- people around the world who depend on fish for their main source of proteins.
The IPCC is now saying that sea-level rise could be as much as  centimeters by the end of this century if we don't cut [greenhouse gas] emissions. But they are certainly predicting more sea level rises than they were last time. And they are also predicting continued major changes in the Arctic Sea ice. So we may see the Arctic without summer sea ice by the middle of the century.
RFE/RL: What will be the impact of the changes in the climate system mean in terms of extreme weather events?
A very significant warming trend [leads to] many extreme events, especially extreme heat events -- heat waves -- but also ocean warming, acidification, changes in the Arctic Sea ice, and also changes in ice on land. So there's also extremely rapid melting now of ice sheets on Greenland and Antarctica, and also glaciers.
RFE/RL: What are the recommendations to policymakers?
Sustained and substantial cuts in greenhouse-gas emissions. This was the main message from scientists. They showed us a scenario for what can happen in the future, but they stressed, again and again, that although we are going to experience warming no matter what -- [carbon dioxide] stays in the atmosphere for a while after it's emitted -- we can still change our future.
RFE/RL: Are you satisfied with the IPCC assessment?
We are very satisfied with the very tough [assessment] and comprehensive process that produced the report. There were -- I think -- nearly 800 scientists involved in this particular report, there were scientists from all over the world, and they came to agreement. And the agreement is very clear: that climate change is happening and our activities, especially burning fossil fuel, is causing it.