It is difficult to estimate how many people are, or will be, displaced by climate change because the capacity of countries to meaningfully monitor this issue is hindered by data-related challenges and knowledge gaps.
This includes problems with the availability, quality, and accessibility of data, the definitions and approaches used to capture the data, and the capacity to analyze it. However, estimates (or, rather, ‘guesstimates’) about the scale of displacement vary from 25 million at the conservative end, to 1 billion in the middle, and 2 billion at the high end.
Acknowledging the risks of climate change, the Parties to the 2015 Paris Agreement agreed to hold the increase in the global average temperature to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels. However, in 2018, the Intergovernmental Panel on Climate Change’s Global Warming of 1.5°C report estimated that global temperatures had already risen by 1.0°C, while warming is likely to reach 1.5°C between 2030 and 2052.
More recently, 11,000 climate scientists announced that they have a moral obligation to advise that planet Earth is facing a climate emergency, and that ‘tipping points’ in the Earth’s climate system could occur from 1–2°C of warming. The World Meteorological Organization also announced that carbon dioxide in the atmosphere hit a record level of 407.8 parts per million in 2018, continuing to rise in 2019. Finally, the United Nations Environment Programme’s Emissions Gap Report 2019 states that countries’ efforts under the Paris Agreement must increase threefold to avoid more than a 1.5°C rise in global warming and fivefold to avoid more than a 2°C rise.
Obviously, these warnings have implications for climate displacement. In a below-2°C scenario, potential losses in developing countries start at US$400 billion per year by 2030 even where US$200 billion worth of adaptation measures are already in place. Yet, as of April 30, 2019, only US$10.2 billion had been pledged to assist developing countries to reduce their emissions and adapt to climate change. This lack of funds for adapting means that the numbers of climate displaced persons (CDPs) is likely to grow significantly.
To better protect CDPs, the Task Force on Displacement, mandated under the Paris Agreement, has recommended that countries adopt the following measures: implement legislation, policies, and strategies to avert, minimize, and address displacement, taking human rights into consideration; map, understand, and manage human mobility; strengthen preparedness, including early warning systems, contingency planning, evacuation planning, and resilience building; integrate human mobility into national planning processes; protect internally displaced persons; and facilitate the orderly, safe, and responsible migration and mobility of people by enhancing opportunities for regular migration pathways.
Further, at the December 2019 Paris Agreement negotiations, the Parties established the Santiago Network to enhance the provision of greater technical assistance to developing-country governments from a range of expert organisations. It can only be hoped that this will remove some of the barriers to climate change adaptation and prevent the worst estimates of climate displacement.
Bodansky, Daniel, Jutta Brunnee and Lavanya Rajamani. 2017. International Climate Change Law. Oxford: Oxford University Press.
Intergovernmental Panel on Climate Change. 2018. Global Warming of 1.5°C. Special Report.
Lenton, Timothy, Johan Rockström, Owen Gaffney, Stefan Rahmstorf, Katherine Richardson, Will Steffen, and Hans Joachim Schellnhuber. 2019. Climate tipping points – too risky to bet against. Nature. November 27.
United Nations Environment Programme. 2019. Emissions Gap Report 2019. November 26.
United Nations. 2015. Paris Agreement.
United Nations. 2018. Global Compact for Safe, Orderly and Regular Migration. July 13.