Climate Change: What the Scientific Record Shows
The documented warming
Global average surface temperature has increased by approximately 1.2 degrees Celsius above pre-industrial levels as of the mid-2020s. This is documented by multiple independent data sets from different countries and methodologies, including surface stations, ocean buoys, weather balloons and satellites.
The rate of warming has accelerated since the mid-twentieth century, corresponding with the large-scale industrialisation of the global economy. The correlation between atmospheric CO2 concentration and temperature is consistent across ice cores, sediment records and direct measurement going back millions of years.
The scientific consensus
The Intergovernmental Panel on Climate Change synthesises research from thousands of scientists across more than 190 countries. Its most recent reports conclude that human influence is unequivocally the dominant cause of observed warming since the mid-twentieth century.
This conclusion is not the property of one country or institution. It is supported by every major scientific body in the world, including those of countries that are significant fossil fuel producers.
What is disputed and what isn't
The fact of warming, and its primary human cause, are not scientifically disputed among climate researchers. What is genuinely debated includes the precise sensitivity of the climate to a doubling of CO2, the regional distribution of specific impacts, the feedback mechanisms that will determine the pace of future change, and the relative effectiveness of different mitigation strategies.
The policy response to climate change, which involves trade-offs between economic interests, timescales and national priorities, is legitimately contested. The physical science is not.
