A slippery slope: How much global warming constitutes ?dangerous anthropogenic interference??

The science underlying global warming, climate change, and the connections between these phenomena are reviewed. Projected future climate changes under various plausible scenarios of future human behavior are explored, as are the potential impacts of projected climate changes on society, ecosystems, and our environment. The economic, security, and ethical considerations relevant to determining the threat posed by climate change are subsequently assessed. The article then discusses the various means available for climate change mitigation, focusing on the relative strengths and weaknesses of various societal alternatives including ‘geoengineering’ and transitioning to less carbon intensive energy sources. The article concludes with the author's views as to what steps might most profitably be taken to avert dangerous anthropogenic interference with Earth's climate, and the ramifications if such steps are not taken.

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Four degrees and beyond: the potential for a global temperature increase of four degrees and its implications

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0303 ◽

2011 ◽

Vol 369 (1934) ◽

pp. 6-19 ◽

Cited By ~ 179

Author(s):

Mark New ◽

Diana Liverman ◽

Heike Schroder ◽

Kevin Anderson

Keyword(s):

Climate Change ◽

Global Warming ◽

Climate Impacts ◽

Climate System ◽

Global Temperature ◽

Sub Saharan Africa ◽

Copenhagen Accord ◽

Sub Saharan ◽

Reduce Emissions ◽

Dangerous Anthropogenic Interference

The 1992 UN Framework Convention on Climate Change commits signatories to preventing ‘dangerous anthropogenic interference with the climate system’, leaving unspecified the level of global warming that is dangerous. In the late 1990s, a limit of 2 ° C global warming above preindustrial temperature was proposed as a ‘guard rail’ below which most of the dangerous climate impacts could be avoided. The 2009 Copenhagen Accord recognized the scientific view ‘that the increase in global temperature should be below 2 degrees Celsius’ despite growing views that this might be too high. At the same time, the continued rise in greenhouse gas emissions in the past decade and the delays in a comprehensive global emissions reduction agreement have made achieving this target extremely difficult, arguably impossible, raising the likelihood of global temperature rises of 3 ° C or 4 ° C within this century. Yet, there are few studies that assess the potential impacts and consequences of a warming of 4 ° C or greater in a systematic manner. Papers in this themed issue provide an initial picture of the challenges facing a world that warms by 4 ° C or more, and the difficulties ahead if warming is to be limited to 2 ° C with any reasonable certainty. Across many sectors—coastal cities, agriculture, water stress, ecosystems, migration—the impacts and adaptation challenges at 4 ° C will be larger than at 2 ° C. In some cases, such as farming in sub-Saharan Africa, a +4 ° C warming could result in the collapse of systems or require transformational adaptation out of systems, as we understand them today. The potential severity of impacts and the behavioural, institutional, societal and economic challenges involved in coping with these impacts argue for renewed efforts to reduce emissions, using all available mechanisms, to minimize the chances of high-end climate change. Yet at the same time, there is a need for accelerated and focused research that improves understanding of how the climate system might behave under a +4 ° C warming, what the impacts of such changes might be and how best to adapt to what would be unprecedented changes in the world we live in.

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Modelling ecosystem adaptation and dangerous rates of global warming

Emerging Topics in Life Sciences ◽

10.1042/etls20180113 ◽

2019 ◽

Vol 3 (2) ◽

pp. 221-231 ◽

Cited By ~ 4

Author(s):

Rebecca Millington ◽

Peter M. Cox ◽

Jonathan R. Moore ◽

Gabriel Yvon-Durocher

Keyword(s):

Climate Change ◽

Global Warming ◽

Diffusion Rate ◽

Individual Species ◽

Genetic Evolution ◽

Rates Of Change ◽

Rapid Climate Change ◽

Warming Climate ◽

Intraspecies Competition ◽

High Trait

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).

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