A new study led by Dartmouth College has assessed the economic impacts that individual countries have caused to other countries through their cumulative national-level contributions to greenhouse gas emissions and the subsequent global warming. These findings provide an essential basis for nations to make legal claims for economic losses caused by emissions.
“Greenhouse gases emitted in one country cause warming in another, and that warming can depress economic growth,” explained study senior author Justin Mankin, an assistant professor of Geography at Dartmouth. “This research provides legally valuable estimates of the financial damages individual nations have suffered due to other countries’ climate-changing activities.”
Professor Mankin and his team found that a small group of the world’s leading national greenhouse gas emitters have caused $6 trillion in global economic losses from 1990 to 2014. While emissions from the United States and China – the world’s leading emitters – are responsible for global income losses of over $1.8 trillion each, economic losses caused by Russia, India, and Brazil exceed $500 billion each.
“This research provides an answer to the question of whether there is a scientific basis for climate liability claims – the answer is yes,” said study lead author Christopher Callahan, a doctoral candidate in Climate Science at Dartmouth. “We have quantified each nation’s culpability for historical temperature-driven income changes in every other country.”
The analysis revealed that the distribution of warming impacts from individual emitters is highly unequal, with the ten leading global emitters causing over two-thirds of losses worldwide. Countries that experience economic losses – due to lower agricultural yields or industrial outputs, and reduced labor productivity caused by climate change – are warmer and poorer than the global average, and are generally located in the global South and the tropics.
“Irrespective of the accounting, warm counties have warmed and lost income because of it, while colder countries have warmed but enjoyed economic gains,” said professor Mankin. “The responsibility for the warming rests primarily with a handful of major emitters, and this warming has resulted in the enrichment of a few wealthy countries at the expense of the poorest people in the world.”
While scientists have previously argued that climate mitigation is a simple “collective action problem,” where no single country acting alone can have an impact of curbing global warming, this study is a first step towards discrediting this idea. “Until now, the complexity of the carbon cycle, natural variations in climate, and uncertainties in models have provided emitters with plausible deniability for individual damage claims. That veil of deniability has now been lifted,” Professor Mankin explained.
“Nations need to work together to stop warming, but that doesn’t mean that individual countries can’t take actions that drive change,” added Callahan. “This research upends the notion that the causes and impacts of warming only occur at the global level.”
Thus, identifying national culpability proves that individual countries can have large, attributable impacts from warming due to their emissions, and that the actions of individual countries do matter. In conclusion, country-level mitigation strategies are worthwhile to pursue and could significantly limit measurable harm to other countries.
The study is published in the journal Climatic Change.