What is ‘climate change’? Is it fact or fiction? Emergency or exaggeration? And can climate change really be responsible for the weird weather that we’ve seen over the past year?
Climate change is the large-term, long-scale shift in the planet’s weather patterns, including rainfall, sea level, and average temperature. In scientific circles, the fact that humans activity is affecting the climate is undisputed; 97% of scientists who have published papers on climate change believe not only that the planet is heating up, but that this warming is most likely due to human activity. Sadly though, there are those who disagree… Cue Donald Trump. (Well I had to mention him at some point!) Any of Trump’s tweets about climate change would do well to prove my point here, but for now let’s just look at his most recent one…
‘In the East, it could be the COLDEST New Year’s Eve on record. Perhaps we could use a little bit of that good old Global Warming that our Country, but not other countries, was going to pay TRILLIONS OF DOLLARS to protect against. Bundle up!’
‘In scientific circles, the fact that humans activity is affecting the climate is undisputed’
As demonstrated so beautifully by the leader of the free world, a big point of confusion (or ignorance), amongst climate change deniers lies in the difference between ‘climate’ and ‘weather’. Whilst weather concerns day-to-day fluctuations in temperature, rainfall etc, climate refers to a long-term trend over years, or even decades. A huge problem in getting across the message of climate change is that it isn’t a sudden process, and so there are no immediate consequences to your actions. This makes it all too easy to pretend that nothing is happening. What we really need to make people sit up and take notice are extreme weather events – occasions in which the weather behaves statistically differently from the average weather in that location. And we are getting just that. 2017 has seen tornadoes, heat waves, flooding and droughts from America to Australia! Here are just a few examples…
- Severe drought across Somalia have brought with them the risk of famine, to the extent that the WHO released an official health warning
- There have been six major hurricanes this year – most notably Hurricane Harvey, which hit Texas in August and caused an enormous 1.2m of rainfall!
- More bad news for America, as wildfires decimated over 245,000 acres of land in California in October
- This year has been the third hottest year since record began! In fact, if you discount the ‘El Nino’ years, during which the planet naturally heats up, 2017 has been the hottest year yet!
So were they caused by climate change? If you were to show a climate scientist a photograph of the devastation caused by Hurricane Harvey and ask ‘Did climate change definitely cause this?’, they would have to answer ‘No’. There is no way of pointing at a specific weather event and saying ‘THIS event was due to climate change’, because every weather event is the culmination of hundreds of different factors. Whilst some scientists use Hurricane Harvey as conclusive proof of climate change affecting our weather, others say that the effect of global warming on this event was minimal, and were furious that the media reporting on Harvey so quickly jumped on climate change bandwagon.
All extreme weather events will have lots of contributing factors, which may or may not include climate change. Extreme event attribution basically tells us how much of an impact climate change had on the event – i.e. increasing the probability of the event happening, or worsening its effects. For example, we can say that the increase in droughts this year is much more likely to be caused by climate change than the increase in tornadoes. Carbon Brief’s study suggests that 63% of all extreme weather events so far were made worse by climate change. Heatwaves account for 46% of these events, droughts for 21%, and heavy rainfall/flooding for 14%.
If there is anything to be gained from these catastrophic events, it’s the shock factor that may finally have finally broken through to some of the climate change sceptics. Whilst it is easy to ignore a scientist with a chart, it is a lot harder to explain away a hurricane sweeping past your front door!
If you want more on the effect of climate change or on natural disasters, check out Tamara Moule’s piece on Hurricane Harvey