I get asked relatively regularly, “Do you believe that climate change is happening?”
Apart from my issue with using the word “believe” in this sentence (but that’s a whole new post), it is actually a valid question.
With so much information available on the topic of climate change, both for and against, how can we know for sure that it’s actually happening?
Unlike other environmental issues, there isn’t one thing that we can decisively point to and say “that’s proof that climate change is happening.” We can look at temperature data, but this doesn’t always provide us with a clear signal. While we can say that many parts of the world are warming, there are also (a few) areas that are cooling. We also see yearly variability in warming trends, caused by natural climate phenomena, such as ENSO, which can confuse long-term signals and cause people to believe that the warming is slowing, or has stopped all together.
We could look at the current atmospheric concentration of CO2 as an indicator of climate change. We know for sure that the concentration is increasing because we can measure it. The problem with using CO2 concentrations as an indicator of climate change, is that at present, the climate has not warmed to the degree that CO2 increases are forcing. There are climate ‘buffers’ at work at the moment, the main one being the ocean, that dampen the degree of climate warming that we should be seeing at this CO2 concentration. So again, this can’t be used as the definitive climate change indicator.
I believe that the answer is that there is no single indicator of climate change, and that’s what makes it such a seemingly confusing issue. It is not until we step back, and look at a whole range of indicators, that we can get an idea of what climate change looks like.
Over the weekend, 350.org held an event called “Climate Impacts Day”. The idea behind this was that we need to “connect the dots” on climate change. Participants from all over the world took photos of themselves, “connecting the dots” on climate. Some of these “dots” included increased frequency of forest fires in Siberia, drought and famine in Kenya, coral bleaching in the Marshall Islands, glacial melting in the USA and beach erosion in Tasmania.
When we stand back and look at the big picture we can clearly see that climate change is real, it’s happening now, and people are already feeling it’s effects.
Check out the slideshow of climate dots.