Some people still talk about the ‘climate change debate’ despite the evidence showing that humans are causing global warming, some people say they don’t ‘believe’ in climate change but belief no longer comes into it.
Human caused climate change has been proven beyond reasonable doubt
Just like weather changes with seasons, climate undergoes periodic changes; in the last 650,000 years, there have been 7 cycles in global temperature. We know this because temperature affects rock formation in a similar way to how it affects tree growth, and just like you can see variations in the seasons over time by looking at a cross section, you can see the growth rate of rocks over a much longer time frame.
The cycle, called the milankovitch cycle, has been consistent for hundreds of thousands of years, but in the last 1300 years the cycle has been broken (1).
Satelite technology has enabled us to see the full picture when it comes to climate at the affects are continuing.
How do we know that it’s caused by humans?
We’ve known about the greenhouse effect since the 1800s – greenhouse gases (mainly water vapour and carbon dioxide) act as a kind of heat shield, keeping warmed air in around the earth and stopping it escaping into space. We also know that human activity causes carbon dioxide to be released into the atmosphere (2), especially activities which involve the burning of fossil fuels for power which takes carbon out of the ground and allows it to reach the atmosphere. This can be seen really clearly in the ‘Keeling curve’ a chart showing the atmospheric carbon dioxide levels taken from a fixed point, and how they’ve changed over time:
You can see they have increased dramatically since the 60s. To put that into context, the following shows how that fits into the bigger picture. The data from before recording began has been found by analysing ice which freezes the atmosphere at the time of freezing in with the water.
- Source: NASA
What about the opposing arguments? Don’t we have to give them a voice?
By giving the other side equal attention it suggests the view may be equally weighted, by using very little or often poor evidence to compare to the strong evidence showing climate change, it suggests that both are equal (or near to it) but they are decidedly not.
97% of climate research agrees that humans are causing global warming (3). Of the 3% remaining there is no consensus between them and suggested causes of global warming include aliens on more than one occasion. Does that seem strange? It may be helpful to know that in October 2015 a study in the Proceedings of the National Academy of Sciences
(PNAS) found that scientists that had taken corporate funding from the likes of Exxon and the Kochs were more likely to produce material designed to polarise the climate change issue – make of that what you will.
Quick fire round
A lot of people who dispute climate change will give clumsy, unsupported arguments and claim that it’s just as reasonable as points from the other side, since those don’t have evidence either – in reality the evidence proving climate change is well established, here are my top three incidences of this:
“The climate is always changing, it has nothing to do with us”
Climate reacts to whatever forces it to change at the time; humans are now the dominant forcing – READ MORE.
“But Hey, it’s getting warmer, tat can’t be a bad thing’
Negative impacts of global warming on agriculture, health & environment far outweigh any positives – READ MORE.
“It will be ok, life adapts”
Global warming will cause mass extinctions of species that cannot adapt on short time scales READ MORE.
The evidence is clear, man made climate change is not a matter of opinion, it’s one of fact. Even calling it the ‘climate change debate’ implies it isn’t a known entity, when in reality, we might as well have a ”Gravity debate’ or a ‘The moon is made of cheese debate” (incidentally there is a fun example of this here – which, I think, reads a lot like the “climate change debate”).
(1) IPCC Fourth Assessment Report, Summary for Policymakers, p. 5
B.D. Santer et.al., “A search for human influences on the thermal structure of the atmosphere,” Nature vol 382, 4 July 1996, 39-46
Gabriele C. Hegerl, “Detecting Greenhouse-Gas-Induced Climate Change with an Optimal Fingerprint Method,” Journal of Climate, v. 9, October 1996, 2281-2306
V. Ramaswamy et.al., “Anthropogenic and Natural Influences in the Evolution of Lower Stratospheric Cooling,” Science 311 (24 February 2006), 1138-1141
B.D. Santer et.al., “Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes,” Science vol. 301 (25 July 2003), 479-483.
“Enhanced Greenhouse Effect”. Ace.mmu.ac.uk. Retrieved 2010-10-15.
Quotation from page 6: “The number of papers rejecting AGW [Anthropogenic, or human-caused, Global Warming] is a miniscule proportion of the published research, with the percentage slightly decreasing over time. Among papers expressing a position on AGW, an overwhelming percentage (97.2% based on self-ratings, 97.1% based on abstract ratings) endorses the scientific consensus on AGW.”