Are stronger typhoons caused by humans? A new global network of climate scientists hope to provide the answers in real-time.
In recent years, scientists have become more adept at working out whether climate change caused by greenhouse gas emissions is exacerbating wild weather and its impacts around the world, but the task usually takes months. Now, a network of climate experts are hoping to tell the world almost in real-time whether global warming has a hand in extreme weather thanks to an initiative they plan to launch by the end of 2015.
“In the media, we are seeing this notion that you cannot attribute any individual events to climate change, but in fact the science has really evolved over the past decade,” says Heidi Cullen, chief scientist with Climate Central. The US-based non-profit science journalism organisation is leading the initiative to speed up that analysis alongside the Red Cross Red Crescent Climate Centre, scientists at Oxford University, the Royal Netherlands Meteorological Institute (KNMI) and others.
A review of 16 major weather events in 2013, published in the Bulletin of the American Meteorological Society on Sept 29, found that human-caused climate change clearly increased the severity and likelihood of five heatwaves studied – including in Australia, Japan and China.
For other events like droughts, heavy rain and storms, pinning down the influence of human activity is more challenging, the researchers say. Human-caused climate change sometimes played a role, but its effect is often less clear, suggesting natural factors are far more dominant.
Back in 2004, a team of British scientists made a splash with a paper estimating that human influence had at least doubled the risk of a heatwave like the one that caused tens of thousands of deaths in continental Europe in the summer of 2003. Since then, the demand to know whether emissions from burning fossil fuels are exacerbating climate and weather extremes has risen, and climate scientists are responding.
In 2011, the Intergovernmental Panel on Climate Change (IPCC) issued a report saying it was “likely” – a two-thirds chance or more – that maximum and minimum daily temperatures around the globe had already increased because of human influences, as had sea levels and coastal high waters. This Sept 29 review is the third edition of the annual study.
Getting the right answers
Maarten van Aalst, director of the Red Cross Red Crescent Climate Centre, says that 10 years ago the Red Cross would not have mentioned climate change in its statements to the media about weather-related disasters. But that is different today.
“There’s a bigger perception that it’s important to know about changing risks – also in the context of recovery and reconstruction (after disasters),” van Aalst said. “Because people recognise that the science is so much stronger”.
The scientists involved in the new attribution initiative are developing a faster system using sophisticated climate models, combined with evidence from historical observations and previous research, that should enable them to say publicly within a couple of days of an extreme weather event happening whether it was made more likely by climate change.
In some cases, there may be no link, and in others, the connection may be weak or uncertain – and that will be clearly stated, says van Aalst.
So far, scientists have found it easier to establish climate change links with natural hazards directly driven by temperature and rising seas, like heatwaves or the storm surge responsible for most of the deaths and destruction when super typhoon Haiyan smashed into the Philippines last November.
But with floods and droughts, which are driven by rainfall, skills are still “emerging”, says Cullen. The goal of the new initiative will be to come up with a “first, best answer to the question when [it] is really on the top of people’s minds” – whether they are journalists, emergency responders, policy makers or affected people. “We really want to make sure we get the answer right,” she emphasises.
Transparency and neutrality
To that end, transparency will be key, and tools will be available so users of the information can understand how it was produced. The events analysed will be selected according to clear criteria to rule out “cherry picking”, adds Cullen. The aim is to cover developing countries, as well as industrialised nations where climate science is better resourced.
Both scientists stress that the new system must be accepted as scientifically sound and politically neutral. That will be especially important in countries like the US and Australia, where the issue of climate change is divisive and large political and business lobbies oppose curbs on emissions.
“What we propose is not an activist campaign to convince people that climate change is the worst problem in the world,” says van Aalst. “It’s about providing honest information that some risks are changing significantly and we need to do something about that.” – Reuters