The current rate of temperature and atmospheric carbon dioxide increase is almost unprecedented in Earth’s entire 4.5-billion-year geological history. The only other time global temperatures and conditions changed this dramatically was when an asteroid hit the Earth 66 million years ago, famously triggering an age of mass extinction and a rapid increase of 5 °C in global temperatures that lasted for roughly 100,000 years.

There are many factors that contribute to climate change, both in the past and in the present. They were present long before humans evolved; however, many things in our modern world produce extra greenhouse gases, like the burning of fossil fuels. Compared to other processes that produce greenhouse gases or warm our planet, how much are humans to blame, and what can we do about it?

The IPCC aims to understand the influences driving the Earth’s climate variability and future climate scenarios. It does not conduct its own research or run models; instead, it provides a meta-analysis of the work of thousands of researchers across the globe to provide a scientific basis for governments to develop climate-related policies. The IPCC warns of risks to food production and security, water availability, species extinction, biodiversity reduction, coastal erosion, floods and droughts, negative impacts on human health, and population displacement. ‘The IPCC has been saying the same thing since the 1990s, but no one is listening,’ said Dr Chloe Mackallah, reading directly from the IPCC’s Fifth Assessment Report, which states that the effects of anthropogenic greenhouse gas emissions ‘are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.’

Warmest congratulations to Dr Samintha Perera, this year’s winner of the Phillip Law Postdoctoral Prize for the Physical Sciences!