July 21, 2012 — andyextance

Based on society’s response to a warming world, we are not building clean power plants fast enough to prevent a 6°C temperature rise compared to pre-industrial levels. According to Andrew Jarvis and colleagues from Lancaster University, UK, current efforts to cut climate-changing CO2 emissions in response to warming aren’t enough to hit the temperature control targets our governments have agreed. Even slightly stronger responses from society to our warming world could be powerful in lowering their prediction – but delaying action means much greater effort will be needed.

We have all probably experienced some strange and perhaps even extreme weather in recent years – some of which has been shown to be down to climate change. But how strong an effect – or feedback – does knowing this have on the CO2 our society emits? That’s the question that Andrew’s team looked at in their paper, published in the scientific journal Nature Climate Change last Sunday.

To do this, they considered worldwide energy use, CO2 emissions and average temperature. Energy usage and emissions have grown at a steadily increasing rate as temperatures have risen over the past 150 years. However, since 1990 the amount of extra electricity each year coming from renewable generation plants, rather than by burning gas or coal that emits CO2, has also grown. That can be thought of as our society responding to warming, even if it isn’t yet enough to slow it down.

“Presumably this is owing to a combination of increased public responsiveness to the risks of climate change during that period and of political action concerning climate change,” Andrew’s team wrote in their paper. “This climate-society feedback has been too weak and short-lived to have caused significant changes… suggesting that, so far, the risks and damages attributed to climate change cannot have been deemed significant enough by society.”

The price of postponed promises

To predict what this level of feedback would have on the future climate, Andrew’s team fed it into a simple climate model. That showed that our current response to higher temperatures is “equivalent to the acceptance of a climate change trajectory ultimately leading to [more than 6°C ] of warming, highlighting the inadequacies of past and present efforts”.

The scientists also wanted to see what it would take to stay within the 2°C temperature rise from pre-industialisation target agreed by world leaders. To do this they looked at what would happen when risk and damage from climate change pushes society into a stronger response, and exactly how strong that feedback needs to be. They found that even a slightly stronger response to temperature rises could easily lower the final warming to 4°C or less, especially if we started to respond sooner rather than later.

However, the timetable politicians agreed last year in Durban, South Africa means serious action to control warming won’t begin until 2020, when the rise is expected to be 1°C already. “To fulfil the outcomes negotiated in Durban in 2011, society will have to become around 50 times more responsive to global mean temperature change than it has been since 1990,” the scientists wrote. “The harder the turning circle the less effective the lever,” Andrew told Simple Climate.

Andrew said that the scientists will follow up this stark message with some “outstanding” further research. But in the meantime he hoped that the idea of climate-society feedbacks will “make decision makers and the public aware of the need to assimilate climate information into personal actions if the climate system is to stabilise on ‘safe’ outcomes”.