The target of limiting global warming to 1.5 degrees Celsius by the end of the century could soon become too economically expensive to justify despite the benefits it could provide, according to a new study by a group of UK academics.
The paper draws attention to studies showing that the carbon price consistent with limiting global warming to 1.5C would be more than US$100 per tonne of carbon-dioxide-equivalent by 2020, and about three times higher than the price required to stop warming of more than 2C.
This study was launched on September 27, just a few days ahead of the release of the Intergovernmental Panel on Climate Change special report on global warming of 1.5C on October 8.
Experts from Imperial College London, the University of East Anglia, and LSE’s Grantham Research Institute on Climate Change and the Environment assessed almost 200 published academic papers on climate change and the feasibility of limiting temperature increases to 1.5C.
From an economist’s point of view, there is an obvious question to ask of the 1.5◦C warming target, in relation to other warming targets: Is it efficient, in the sense of increasing welfare? In more straightforward terms, will the benefits to society of limiting warming to 1.5◦C exceed the costs? This is the primary focus of the study which appears in the Annual Review of Environment and Resources journal.
Lead author, Prof Simon Dietz of the ESRC Centre for Climate Change Economics and Policy and the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science explained that “the evidence we have simply does not give us a clear answer on whether the benefits of limiting warming to 1.5C exceed the costs. But if we want to keep the option open to limit warming to 1.5C, then unless we discover a much cheaper way to remove carbon dioxide from the air, and if we want to avoid risky methods of blocking out sunlight, we have to pursue the goal of 1.5C now.”
The paper acknowledges the larger financial investments required to cut emissions sufficiently to limit global warming to 1.5C instead of 2C, particularly if policies are not designed well. It states: “The remaining carbon budget consistent with 1.5C is very small and the global economy would need to be decarbonized at an unprecedented scale to stay within it, likely entailing larger costs.
“Any further delay in pursuing an emissions path consistent with 1.5C likely renders that target unattainable by conventional means, instead relying on expensive large-scale CDR (carbon dioxide removal), or risky solar radiation management.”
Co-author Prof Rachel Warren from UEA’s Tyndall Centre for Climate Change Research said: “Our review of recent studies shows the significant projected benefits of limiting global warming to 1.5C rather than 2C above pre-industrial levels for both human and natural systems. These benefits include preservation of Arctic sea ice, reduced biodiversity loss, and reduced damage to coral reefs.”
The study states that adoption of the 1.5C ceiling suggests three priorities for policy making. First, successive UNFCCC summits must keep up the pressure on countries to adopt more ambitious Nationally determined Contributions (NDCs).
Second, the flow of finance to developing countries that adopt strong NDCs must be increased. The theoretical desirability of a global carbon price depends on there being appropriate lump-sum transfers to compensate the heaviest losers. Various schemes have been devised for equitable transfers among nations to accompany global carbon pricing, or other ways to make climate action fair. Empirically, it appears that mitigation opportunities are disproportionately concentrated in developing countries. Without appropriate receipts, developing countries will be unlikely to set as high a carbon price as developed countries, with adverse consequences for global efforts on aggregate and for cost-effectiveness.
Third, better mechanisms to encourage the international dissemination of low-carbon technologies are required. These could build on the global Technology Mechanism established by the Paris Agreement, but they need to be incorporated in broader efforts to promote sustainable low-carbon development, as well.
At the Paris COP21, countries sought advice and guidance from the world’s top climate scientists, the IPCC, on how the Paris goal could be achieved given that the ambitious 1.5C global warming limit entails drastic and immediate decarbonization of the global economy.
Global leaders, together with the United Nations System, have called on all Parties and non-party stakeholders to step up action at all levels in view of the inadequacy of prevailing policies and pledges to meet the goals of the Paris Agreement, in particular the limit it sets on the rise of global temperature at 1.5C, explained Secretary Emmanuel De Guzman of the Philippines’ Climate Change Commission.
The 2015 Paris Agreement saw countries pledge to limit global warming to well below 2C, and to aim to keep it within 1.5C. The problem is that countries’ current emissions targets are not enough to meet these goals.
“ There is no choice but to do more. Business-as-usual inaction brings the planet in the range of 4C to 6C of warming level by the end of the century. The current pledges of countries submitted to the UNFCCC in Oct 2015 in the form of Intended Nationally Determined Contributions or INDCs prove insufficient given that they would result in a 3C warming level, way beyond the 1.5C ambition and 2C ultimate limit set in the Paris Agreement,” De Guzman said.
What are the most urgent measures for us to get onto a 1.5C pathway?
Various experts and sources recommends measures such as rapid scaling up of renewable energy systems, increased energy efficiency at all levels to reduce the growth in primary energy demand (achieved through electrification of transport systems, improvements of industrial and building efficiency, and other energy-saving technologies), and the use of renewables and other low-carbon energy systems to enable the rapid decarbonization of what fuels a country’s sustainable development.
“ Globally, the direct mitigation costs of 1.5C is estimated to be from 1.5C higher to twice the costs of the 2C-limit over the whole 21st century but the benefits are many, and may mean survival for a number of the most vulnerable countries,” explained Lourdes Tibig, climatologist and member of the National Panel of Technical Experts convened by the Climate Change Commission. “ In summary, limiting the long term global temperature increase to 1.5C requires urgent actions and deep cuts on greenhouse gas emissions, particularly for developed countries.”
“ Fossil fuel CO2 emissions should be reduced as rapidly as practical. The longer we postpone concerted global action, the more expensive will it be, both in terms of mitigation costs and in terms of adaptation to negate projected negative impacts,” Tibig said.
Tibig added that for the most vulnerable countries, such as the Philippines, there is a need to strive to achieve its goals for low-carbon development, including what the country proposed in its NDCs. “That is without losing sight of the need for continuous efforts to build climate and disaster risks resilience as we look to the certainty that because of regional differences we will be having overshoots in our 1.5C target,” Tibig said.
The Institute for Climate and Sustainable Cities, in collaboration with the Climate Change Commission, where the IPCC will present, through a global live stream, the Summary for Policymakers of the Special Report on Global Warming of 1.5C. The event set on October 8, will also tackle a briefing on the global and national impacts of climate change, including its implications on the Philippine economy and long-term development policy.
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