Volume 5 Issue 1 of the Asian Economic Policy Review published in July 2010 was devoted to the theme of "The Environment and Climate Change." What has changed since 2010 that justifies devoting another issue to a similar theme 10 years or so later? The economics underlying climate change as spelled out clearly in Stern (2007) have not changed, although we probably have a better understanding of the impact of emissions trading mechanisms introduced following the adoption of the Kyoto Protocol. The Kyoto Protocol which came into force in February 2005 committed industrialized countries and countries in transition to limit and reduce greenhouse gases (GHG) emissions in accordance with agreed individual targets. As Arimura and Sugino (2021) discuss, the time since 2005 provide us with data and experience with the trading of emission permits and carbon pricing which were established by the Kyoto Protocol. One of the important changes in the international environment that has occurred between 2010 and now is the Paris Agreement that entered into force on November, 4, 2016. The Paris Agreement aims to keep the global temperature rise this century to below 2 o C above pre-industrial levels, and to limit the increase even further to 1.5 o C. Importantly, this agreement, which covers both developed and developing economies, requires all signatories to put forward their best efforts through "nationally determined contributions." As Table 1 indicates, 9 of the top 10 greenhouse gas (GHG) emitters, including China, the largest GHG emitter by far, have ratified (or in the case of Japan, accepted) the treaty governing the Paris Agreement by early November 2016. However, the position of the USA has been problematic. Under the Obama Administration, the USA ratified the treaty on 3 September 2016, but on 1 June 2017 President Donald J. Trump announced his intention to withdraw from the agreement, and the USA formally withdrew from the agreement on 4 November 2020. The next day, Presidentelect Biden stated that "in exactly 77 days, a Biden Administration will rejoin it"
