What are the odds that climate change is the work of natural processes, rather than human activity? As small as one in a thousand, according to a new scientific study based on empirical evidence.
Rather than using advanced climate modeling techniques to look into the future, physics professor Shaun Lovejoy, of McGill University in Quebec, used historical – and more tangible – data to look into the past to question whether manmade emissions are the cause of global warming,
“This study will be a blow to any remaining climate change deniers”, Lovejoy said.
“Their two most convincing arguments – that the warming is natural in origin, and that the computer models are wrong – are either directly contradicted by this analysis, or simply do not apply to it.”
Such records revealed that the pattern of warming before mankind began pumping greenhouse gases into the atmosphere do not match up to what has happened since.
From this, Lovejoy concluded that the hypothesis that global warming since 1880 has occurred naturally can be ruled out “with confidence levels great than 99%, and most likely greater than 99.9%.”
“We’ve had a fluctuation in average temperature that’s just huge since 1880 – on the order of about 0.9C”, he added.
“This study shows that the odds of that being caused by natural fluctuations are less than one in a hundred and are likely to be less than one in a thousand.”
Lovejoy’s 99% confidence is close to the degree of certainty that the scientific community has over mankind’s influence on the climate.
The Intergovernmental Panel on Climate Change asserts with 95% confidence that humans are the main cause of global warming, while just one scientific paper out of 2,258 published in 2013 suggested otherwise.
Lovejoy added, “While the statistical rejection of a hypothesis can’t generally be used to conclude the truth of any specific alternative, in many cases – including this one – the rejection of one greatly enhances the credibility of the other.”
Photo: Gerald Simmons via Flickr