Climate change is overwhelmingly caused by the emissions of greenhouse gases (GHG) from human activities. This briefing note argues that existing data and understanding are sufficient to make a sound estimation of each country’s contribution to climate change. For this reason, lack of data should not be a hindering factor in decisions around legal obligations.
Global greenhouse gas (GHG) emissions have continued to rise in the past decade, despite the urgent need to reduce emissions to tackle climate change. Continued GHG emissions will cause further climate change, with increasingly severe impacts and risks.
Previous research, led by Matt Jones from the Tyndall Centre for Climate Change Research at the University of East Anglia (UEA), helped determine national contributions to climate change due to historical emissions of greenhouse gases, including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). This research calculated the global mean surface temperature response to historical emissions of the three gases, taking into account the properties of the gases.
While there has been progress in tackling climate change in certain sectors and counties, so far, these actions have not been deep or widespread enough to reverse global GHG emissions and put them on the trajectory towards Net Zero. Notably, 26 countries have succeeded in significantly decreasing their CO2 emissions from fossil fuels in the past decade (2013-2022), while growing their economies, demonstrating that progress in tackling climate change is possible.
This independent expert report was produced at the request of the counsel for the Republic of Vanuatu. It forms part of their written statement to the International Court of Justice (ICJ), to inform the Court’s Advisory Opinion on the Obligations of States in respect of Climate Change, requested by the UN General Assembly.
This is the first time that the UN has adopted such a request by consensus, and the first time that the ICJ will take a position on climate change. The landmark case by the Court seeks a non-binding advisory opinion on the obligations of States to prevent and address climate change.
Professor Corinne Le Quéré, Royal Society Research Professor of Climate Change Science at UEA, and author of the report, said:
“Strong directives from the ICJ would provide additional incentives for countries to accelerate their responses to climate change. At a time when climate change is intensifying weather extremes such as floods and wildfires, the damages to other countries and to people today and tomorrow are quickly ramping up.”
Prof Le Quéré and colleagues at the Tyndall Centre at UEA have developed two data-sharing applications which show the contribution of each country to climate change. The applications enable users to explore the contributions to climate change by States, by gas, for fossil fuels and land use individually, and for different time periods.
Attribution of observed global warming to countries