Global mismatch between greenhouse gas emissions and the burden of climate change

Abstract

Countries export much of the harm created by their greenhouse gas (GHG) emissions because the Earth's atmosphere intermixes globally. Yet, the extent to which this leads to inequity between GHG emitters and those impacted by the resulting climate change depends on the distribution of climate vulnerability. Here, we determine empirically the relationship between countries' GHG emissions and their vulnerability to negative effects of climate change. In line with the results of other studies, we find an enormous global inequality where 20 of the 36 highest emitting countries are among the least vulnerable to negative impacts of future climate change. Conversely, 11 of the 17 countries with low or moderate GHG emissions, are acutely vulnerable to negative impacts of climate change. In 2010, only 28 (16%) countries had an equitable balance between emissions and vulnerability. Moreover, future emissions scenarios show that this inequality will significantly worsen by 2030. Many countries are manifestly free riders causing others to bear a climate change burden, which acts as a disincentive for them to mitigate their emissions. It is time that this persistent and worsening climate inequity is resolved, and for the largest emitting countries to act on their commitment of common but differentiated responsibilities.

Figure 1. Global inequity in the responsibility for climate change and the burden of its impacts.

(a) Climate change equity for 2010. (b) Climate change equity for 2030. Countries with emissions in the highest quintile and vulnerability in the lowest quintile are shown in dark red (the climate free riders), and those countries with emissions in the lowest quintile and vulnerability in the highest quintile are shown in dark green (the climate forced riders). Intermediate levels of equity are shown in graduating colours, with countries in yellow producing GHG emissions concomitant with their vulnerability to the resulting climate change. Data deficient countries are shown as grey. Maps generated using ESRI ArcGIS.

Figure 2. Vulnerability to climate change, mean GHG emissions, and mean GDP.

(a) Number of countries in each climate change vulnerability category, derived from DARA vulnerability data, for 2010 (blue bars) and 2030 (green bars). (b) Mean GHG emissions for 2010, derived from CAIT GHG emissions data, shown in CO₂ equivalent units and climate vulnerability categories for 2010 (blue bars, with standard error) and 2030 (green bars, with standard error). (c) GDP shown in current US$ (in billions), derived from the World Bank GDP 2010 data, and 2010 GHG emissions. (d) Mean GDP for 2010 shown in current US$ (in billions) and climate change vulnerability for 2010 (blue bars, with standard error) and 2030 (green bars, with standard error).