The world is changing
DEAR SIR — We are living in a changing world. Last year was among the 10 warmest years on record — continuing the long-term trends we have seen in our changing and varying climate. As CO levels continue to climb, these changes are not just confined to global temperatures. Keeping sight of the bigger picture shows evidence of a changing world in rising sea levels, melting Arctic sea ice, and shrinking ice sheets.
And this evidence is indisputable. Observations across the climate system show a warming planet. The fundamental physics is clear; CO traps radiation and warms the planet. If we increase CO levels in the atmosphere, temperatures will rise.
Last year, and again this year, many parts of the world have been affected by damaging and costly extreme events; from major heat waves, droughts and wildfires to extreme cold, excessive rainfall and flooding. Thousands of lives have been lost, over 100-million people have been affected and the damages run to tens of billions of pounds.
A new paper by scientists from the UK and the US provides evidence that human influences on the climate played a role in the severity of a number of these events. The paper concludes that the frequency of occurrence of the extreme heat experienced in the US last year is four times more likely as a result of human-induced climate change, and that climate change contributed about 35% of the high temperatures in the eastern US between March and May.
It also highlights the increasing risks of coastal inundations from events such as Hurricane Sandy, which broke 16 historical storm-tide levels along the US east coast. Increases in sea level related to climate change have nearly doubled today’s annual probability of a Sandylevel flood compared to 1950. As sea levels continue to rise, coastal communities face a looming crisis with an increased frequency of flood events on a par with Sandy but from storms of less intensity and lower storm surge.
The paper’s authors are rightly cautious in not overstating the case for human influences on extremes, in particular those related to extreme rainfall. What is clear is that climate change is already costing us dearly, and that when combined with growing population and urbanisation, is projected to disrupt regional and global energy, food, water and health security.
It can often be all too easy to focus on minutiae; to burrow down into the proverbial rabbit hole. But the world is changing and we are playing a part.