Address from the Editor-in-Chief
Significant Achievements of 2020 (29th) Blue Planet Prize laureates
Response to Biodiversity Loss Is the Most Urgent Issue. - Prioritizing Global Environmental Problems
Although there are differences of opinion about which is the greatest priority among the many global environmental problems we face; the following are generally considered major issues: climate change; shrinking tropical rainforests; the decline of biodiversity; marine pollution; acid rain; and the transfer of hazardous waste to developing countries.　
Previously, some people classified environmental problems into 25 groups, and some of them were left unattended at that time even though they were solvable. However, most of them have been or are being improved. For example, destruction of the ozone layer was greatly mitigated by replacing chlorofluorocarbons (CFCs) with compounds having shorter atmospheric lifetimes. With financial support from developed countries, the problem of acid rain can be resolved by removing sulfur from fossil fuels. Also, the transfer of hazardous waste to developing countries can be reduced as individual nations increasingly process and dispose of their waste within their own borders.
Then, what are the issues that must be worked on over the long term? One of them is climate change, which requires the reduction of CO2 emissions on a global scale. Owing to the financial sectors’ recent change of stance regarding climate change issues, a number of developed countries seem to have started searching for a solution to climate change, and it is likely that some measures will have been implemented by 2050. The same can be said of the acid rain problem. Remaining long-term problems include the loss of tropical rainforests, decreasing biodiversity, and marine pollution. As the problem of decreasing biodiversity will not be solved without finding solutions to marine pollution and the loss of tropical rainforests, it seems to me that decreasing biodiversity is and will be the most critical environmental problem.
What leads to the decline of biodiversity? The reasons for decreasing biodiversity are diverse. For example, beautiful tropical birds might be captured and stuffed for commercial trade. To fight this, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (Washington Convention, or CITES) was established in 1975.
What can we do to prevent the loss of biodiversity? We must carefully review our activities, assess our impact on the environment, and share the knowledge and results.
The winners of the 2020 Blue Planet Prize are individuals who recognize the importance of biodiversity and have worked over decades to preserve it.
Professor Tilman of the United States showed us the negative impact of agriculture and dietary habits on human health and the global environment. He showed us the particularly harmful effects of red meat on both human health and the environment. It seems to me that we need to be gradually shifting to a vegetarian diet.
Dr. Stuart of the United Kingdom led the development of the categories and quantitative criteria for the IUCN Red List of Threatened Species and contributed significantly to the expansion of the number of species assessed. Humans are at the top of the ecological pyramid; however, our existence is entirely dependent on other species, which is the essence of what we should be deeply aware of.
How should we assess the level of importance of various global environmental problems? Although this topic has yet to be fully discussed, I believe that we should assess issues from the viewpoint of irreversibility. In other words, we must figure out what type of issue becomes irreversible once it passes a tipping point and then give priority to working on it. As for climate change, or more specifically global warming, it takes a long time to mitigate it. A prompt response is required before it is too late. The extinction of species is a typical example of an irreversible event. We need to be aware that once species become extinct, they are gone forever. I believe that the greatest task of humans is to act with the aim of zero extinction of species while appreciating the important role of each species on the planet.
Itaru Yasui
Former Vice-Rector, United Nations University
Professor Emeritus, The University of Tokyo