By Rob Plastow
This week the science journal Nature published two major pieces of research that may change the way we think about observing the links between single events and global warming.
One of the studies focuses on an event that can easily be recalled to memory by people in the UK of voting age, and can potentially make connections in the mind between then, now and climate change in a way that heretofore would have mostly resided in speculation. In doing so, it helps to make global warming more tangible, albeit still ever elusive and complex.
Back in 2000, I used to walk to college everyday from my then home of the Quay in Exeter, Devon. One September afternoon I clearly remember getting drenched in a downpour that had been a part of a spate of rain that had caused the River Exe to burst its banks. Much of the Exe Valley between Exeter and Tiverton was flooded and the rising of the Exe also caused the Quay itself to become a good few feet under water.
I had never, and to this day still have not, experienced quite the drenching I got that day walking through fast flowing streams over the city’s concrete and tarmac. I soon became so wet that I quickly reached the point of no longer caring as there was no where on my body left to be drenched.
At the time I remember cursing the increased amount of roads and concrete that may have led to increased run-off and therefore contributed to the floods but my thoughts did not immediately point the blame towards climate change. Weather is not climate, and in the middle of that down pour as much as I may have pondered the connection, such a claim could not be made.
Whilst watching the reporting and coverage of floods, hurricanes and other weather events that have had considerable impact over the decade since, I have often wanted to know if they are indicative of changes caused by global warming. Freak floods, heatwaves, droughts, increased numbers of events and so on seemed to be pointing towards climate change in my mind but that is not to say there is a demonstrable link between the two – climate science is anything but black and white.
Could it have also been that with the arrival of 24 hour news channels and my increased use of the internet for news and information, I and many others like me were and are, simply finding more information and being bombarded with coverage that in earlier years would have gone unseen or unheard?
So this week’s news came as welcome relief for my ponderings over a decade ago whilst drenched on my walk home from college.
The first study in the much discussed issue of Nature highlights how human induced increases in greenhouse gases have contributed to the observed intensification of heavy precipitation events in the Northern Hemisphere. The second shows that it is ‘very likely’ that global anthropogenic greenhouse gas emissions substantially increased the risk of flood occurrence in England and Wales in the autumn of 2000, in which I only got soaked whilst many others suffered severe damage to their property and homes or their health.
The researchers in the latter study used several thousands of computer modelled sequences to determine whether increased CO2 levels affected the probability of the event occurring. They looked at scenarios with and without human induced greenhouse gas releases and found that in 9 out of 10 cases their model results indicated that twentieth-century anthropogenic greenhouse gas emissions increased the risk of floods occurring in England and Wales in autumn 2000 by more than 20%, and in two out of three cases by more than 90%.
Not only I am glad to know that climate modelling and science is getting better, but I’m hopeful for how the study may change the way insurers, policy makers and leaders are going to have to think about climate change adaptation from now on when they deal with assessments of risk, probability and responsibility.
If the results of these two studies add to their understanding of global warming, as they have to mine, as a real and direct threat to today’s world and not just some distant future, perhaps they will help us move forward with speed and help us avoid getting caught in a storm.
