The statistics community is a champion of evidence-based decision-making, accounting for uncertainties. These qualities are needed to address the challenge of climate change.

There is ample evidence that the climate is changing in response to human activities. Specifically, there is extensive instrumental evidence that ambient and ocean temperatures have been rising over the last century, with surface temperature having risen by approximately 1 °C since pre-Industrial levels globally¹ and in Australia², and it is continuing to rise. The mechanism by which this is happening is well understood, and is primarily due to increasing concentrations of greenhouse gases in the atmosphere. In particular, atmospheric carbon dioxide concentrations have increased to 40% above pre-industrial levels at an accelerating rate. This is largely due to human activity, especially the burning of fossil fuels, but also deforestation. Evidence for the above come from a range of sources, and the core arguments are not a subject of continuing scientific debate, and have been widely accepted in the scientific community for a long time³.

Risk is a key consideration in decision-making. While the precise future costs of climate change are uncertain, they are expected to be considerable. We are currently estimated to be on a path towards 3 °C warming since industrialisation, even after accounting for commitments at the 2015 Paris Agreement, when even 1.5 °C warming poses a serious danger to food security, water supply, biodiversity, and beyond^2,4. The slower the efforts to mitigate climate change, the stronger the effects will be. Given that the future cost of climate change is likely to be very large, compared to the costs of taking action to address it⁵, the rational approach to this problem is to take strong climate action now.

1 International Panel on Climate Change (2013), “Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (Summary for Policy-Makers)” https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_SPM_FINAL.pdf

2 Bureau of Meteorology and CSIRO “State of the Climate 2018” https://www.csiro.au/en/Showcase/state-of-the-climate

3 N. Oreskes, “Beyond the Ivory Tower: The Scientific Consensus on Climate Change,” Science Vol. 306 no. 5702, p. 1686 (3 December 2004) https://science.sciencemag.org/content/306/5702/1686

4 International Panel on Climate Change (2018), “Global Warming of 1.5°C” https://www.ipcc.ch/sr15/

5 Stern, N. (2006). "Stern Review on The Economics of Climate Change". HM Treasury, London. https://webarchive.nationalarchives.gov.uk/+/http:/www.hm-treasury.gov.uk/media/4/3/executive_summary.pdf