In the case of an injury, sometimes an emergency situation is obvious, and often only a careful examination looking for signs of a worst case outcome reveals an emergency response situation. The same applies to an environmental health threat.
The impacts of allowing global climate change to continue have been known for decades.
Pollution. The issue is one of pollution - sources of atmospheric greenhouse gas pollution which is the worst ever environmental health hazard. We have had many decades of experience in assessing risks of pollution.
However climate change assessments do not use a pollution risk assessment approach.
A best guide we have is the 2010 A Human Health Perspective on Climate Change published by Environmental Health Perspectives and the National Institute of Environmental Health Sciences. The flow chart (above) from the publication shows the many more essential aspects and connections of a proper environmental risk assessment that the climate change assessments.
The other essential aspect that all the environmental health science agrees with is the involvement at the start of public stakeholders.
The 2007 IPCC AR4 assessment showed clearly from all the impacts on billions of people and on future generations that 2°C is disastrous (as James Hansen has said) and that for vulnerable populations 1°C is the danger limit.
"The stated goal of the UNFCCC – avoiding dangerous anthropogenic interference in the climate – is in fact unattainable, because today we are already experiencing dangerous anthropogenic interference."
— John P. Holdren, Distinguished Scientist Seminar, 3 Nov 2006 Meeting the Climate Change Challenge. (Dr. Holdren was US Presidential Science Advisor, Professor of Environmental Policy at Harvard University, and Former President of the American Association for the Advancement of Science)
Even so, no one has submitted that this is the case to the United Nations climate negotiations. As a result, the negotiators are not under pressure to reach an agreement and the industrialized nations are not being held accountable under international law.
Dangerous interference with the climate system refers to atmospheric greenhouse gas concentrations. The distinction between dangerous interference and dangerous climate change is most important because of the basic science of greenhouse gases in the atmosphere and how planetary systems respond to atmospheric greenhouse gas warming.
The science of global climate change is characterized by long lag times between emissions of greenhouse gases and their impact being experienced by ecosystems, species and human populations on the planet. Put simply, the cause and effect relationship between atmospheric greenhouse gases and their global warming means that at any particular time and global average temperature increase, that particular temperature increase is bound to be doubled in the future and that the increased temperature and all global climate change impacts will last for over 1000 years.
RISK MANAGEMENT AND CLIMATE CHANGE by Howard Kunreuther et al. was published in Nature 2013. It is the latest we have published by the climate science.
The Bradford Hill risk criteria (9) remain a basis of toxicology to determine causation. Climate change assessments seek cause and effect rather than causation.
Reasons For Concern
RFC1 Unique & threatened systems: ecological and human systems that have restricted geographic ranges constrained by climate-related conditions and have high endemism or other distinctive properties. Examples include coral reefs, the Arctic and its Indigenous People, mountain glaciers and biodiversity hotspots.
RFC2 Extreme weather events: risks/impacts to human health, livelihoods, assets and ecosystems from extreme weather events such as heatwaves, heavy rain, drought and associated wildfires, and
coastal flooding.
RFC3 Distribution of impacts: risks/impacts that disproportionately affect particular groups owing to uneven distribution of physical climate change hazards,
exposure or vulnerability.
RFC4 Global aggregate impacts: impacts to socio-ecological systems that can be aggregated globally into a single metric, such as monetary damages, lives affected, species lost or ecosystem degradation at a global scale.
RFC5 Large-scale singular events: relatively large, abrupt and sometimes irreversible changes in systems
caused by global warming, such as ice sheet disintegration or thermohaline circulation slowing.