Major New Climate Report from the IPCC Reveals Human Impact Is 'Unequivocal' -- Global Response Needed
Photo Credit: AFP
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World leaders must now respond to an "unequivocal" message from climate scientists and act with policies to cut greenhouse gas emissions, the United Nations secretary-general urged on Friday.
"The heat is on. We must act," said Ban Ki-moon, as he invited world leaders to a special summit next year to forge a global agreement on emissions.
The world's leading climate scientists, who have been meeting in all-night sessions this week in the Swedish capital, said there was no longer room for doubt that climate change was occurring, and the dominant cause has been human actions in pouring greenhouse gases into the atmosphere.
In their starkest warning yet, following nearly seven years of new research on the climate, the Intergovernmental Panel on Climate Change (IPCC) said it was "unequivocal" and that even if the world begins to moderate greenhouse gas emissions, warming is likely to cross the critical threshold of 2C by the end of this century. That would have serious consequences, including sea level rises, heatwaves and changes to rainfall meaning dry regions get less and already wet areas receive more.
In response to the report, the US secretary of state, John Kerry, said in a statement: "This is yet another wakeup call: those who deny the science or choose excuses over action are playing with fire."
"Once again, the science grows clearer, the case grows more compelling, and the costs of inaction grow beyond anything that anyone with conscience or commonsense should be willing to even contemplate," he said.
He said that livelihoods around the world would be impacted. "With those stakes, the response must be all hands on deck. It's not about one country making a demand of another. It's the science itself, demanding action from all of us. The United States is deeply committed to leading on climate change."
In a crucial reinforcement of their message – included starkly in this report for the first time – the IPCC warned that the world cannot afford to keep emitting carbon dioxide as it has been doing in recent years. To avoid dangerous levels of climate change, beyond 2C, the world can only emit a total of between 800 and 880 gigatonnes of carbon. Of this, about 530 gigatonnes had already been emitted by 2011.
That has a clear implication for our fossil fuel consumption, meaning that humans cannot burn all of the coal, oil and gas reserves that countries and companies possess. As the former UN commissioner Mary Robinson told the Guardian last week, that will have "huge implications for social and economic development." It will also be difficult for business interests to accept.
The central estimate is that warming is likely to exceed 2C, the threshold beyond which scientists think global warming will start to wreak serious changes to the planet. That threshold is likely to be reached even if we begin to cut global greenhouse gas emissions, which so far has not happened, according to the report.
Other key points from the report are:
• Atmospheric concentrations of carbon dioxide, methane and nitrous oxide are now at levels "unprecedented in at least the last 800,000 years."
• Since the 1950's it's "extremely likely" that human activities have been the dominant cause of the temperature rise.
• Concentrations of CO2 and other greenhouse gases in the atmosphere have increased to levels that are unprecedented in at least 800,000 years. The burning of fossil fuels is the main reason behind a 40% increase in C02 concentrations since the industrial revolution.
• Global temperatures are likely to rise by 0.3C to 4.8C, by the end of the century depending on how much governments control carbon emissions.