Defining Dangerous Climate Change


This page explains one particular vital, yet missing, aspect of the climate change emergency that the medical profession can respond to.

The United Nations Framework Convention on Climate Change (UNFCCC) speaks of "dangerous anthropogenic interference with the climate system" but the Intergovernmental Panel on Climate Change will not define it.

Global Warming Thermometer

"The Intergovernmental Panel on Climate Change (IPCC) is charged by the United Nations Environment Program to assess climate change risks in a way that informs, but, importantly, does not prescribe the government policies necessary to avoid DAI [dangerous anthropogenic interference with the climate system]. It is therefore not surprising that the IPCC stops short of defining what DAI actually is, let alone advocating policies designed to avoid it."

— Michael Mann, in Defining dangerous anthropogenic interference (PNAS, March 2009)

No formal position on defining dangerous climate change

Although it is hard to believe, there is no formal international, national, or science policy position that the world is beyond dangerous interference with the climate system, according to the clear intent and terms of the 1992 UN climate change convention (UNFCCC).

The one thing agreed on is that it means a dangerous atmospheric concentration of greenhouse gases.

However, even with CO2 concentrations in the atmosphere higher than at any time in the last 15 million years, and with methane concentrations 2.5 times higher since industrialization, we have no agreed policy position that this is beyond dangerous, and there has been no submission to the UN climate change convention secretariat that we are beyond dangerous.

The first individual expert to say that we are "beyond dangerous" was John Holdren (science advisor to US President Obama) in his 2006 climate science presentation, Meeting the Climate Change Challenge. Other notable leading climate change scientists who have made public and written statements that we are beyond dangerous climate interference are James Hansen, Hans Schellnhuber, and Bill Hare.

Although it is clearly and specifically defined by the UNFCCC, climate change scientists say that "dangerous" cannot be defined by science.

The climate scientists say that dangerous climate change cannot be defined by science because that would be a "value judgement" that scientists cannot make. The IPCC says that only policy makers can make such value judgements on dangerous climate change.

Defining dangerous climate change through "risk"

Is it possible for science to define and advise on "dangerous" climate interference? Fortunately, it is not strictly true that danger cannot be defined. Danger is quantified in science and policy by "risk."

Risk is defined by the precautionary formula:

Risk = Probability x Magnitude

This formula is endorsed by the IPCC.

Following the medical and environmental health model could get us around the problem of dangerous being deemed a value judgment that science cannot make.

The fact is, dangers are routinely assessed by doctors (who are scientists) who give recommendations as prescriptions for treatment. Obviously they have to do this to protect the health and lives of their patients. Another, even closer, medical example is deciding if a substance is a hazardous toxin and whether it needs regulation.

The committed climate change situation is the same, but billions of lives are at stake.

Do the IPCC's 5 Reasons for Concern define dangerous climate change?

The IPCC assessment includes five reasons for concern, to guide policy makers.  

The Reasons for Concern are:

  1. Risks to unique and threatened systems
  2. Risks of extreme weather events
  3. Distribution of impacts and vulnerabilities
  4. Aggregate impacts
  5. Risks of large-scale singularities.

The March 2009 Copenhagen Climate Congress, which was held to update the science of the 2007 IPCC assessment, also said that the scientists cannot give an opinion on dangerous climate interference as this can only be done by "society in general."

This is an enormous problem — but one that the medical profession has a solution for.

  • Still, there is no official definition of what "dangerous interference with the climate system" means for the UN climate convention negotiations or for national climate policy making.

  • The danger limit being used for climate change policy is a global average temperature rise of 2ºC above the pre-industrial level. But this is an informal political target rather than a scientifically determined danger limit (though it is now endorsed by scientific organizations).

  • The published science to date shows that +2ºC is an intolerably dangerous target to aim for, by any definition. Indeed, it should not be targeted at all, and should be avoided at all costs. One hundred of the world's most vulnerable nations have asked for the under 1.5C policy option, but this is still only being considered, and 2C still remains the focus

  • However, the current science also says we cannot avoid a global warming of far above 2ºC without a drastic planetary emergency response — an immediate decline in our greenhouse gas emissions, achieving zero carbon by 2050 — and possibly the development of new technologies to remove carbon dioxide from the atmosphere.

Global Warming Thermometer

It is clear the current level of interference is dangerous. The question is to avoid catastrophic interference.

— John Holdren, President
American Academy for the Advancement of Science, 2007
to the UN General Assembly Thematic Debate on 
"Climate Change as a Global Challenge"

The role of health care professionals in defining dangerous climate change

Doctors and other health professionals are well qualified to define "dangerous" when it comes to risk aversion and adverse effects on human health and well-being.

Helping to define "dangerous" in the context of global climate change is an invaluable contribution that the medical profession can make to urgent international negotiations. However, these negotiations for a Kyoto Protocol replacement agreement to safeguard the health and survival of life on Earth are on hold. States have decided there will not be new measures until after 2020.

Medical professionals know very well what "dangerous" means. And they know what dangerous climate change is. Indeed, climate change is beyond dangerous when people are dying in global warming-related storms, floods and droughts (Africa and Asia, even New York City), and having to flee their homes due to permafrost melt (the North) or rising sea levels (small island nations). We are all now facing an increasing risk of catastrophic climate change.

Physicians presenting at climate change conferences and the public statements made by national medical associations and public health organizations have already addressed the issue of dangerous climate change impacts and risks.

With the deplorable lack of political will to mitigate catastrophically dangerous climate change, it is now time for medical organizations and other concerned professional associations to make formal submissions on the emergency, and for the medical and health care community, in particular — with their great influence — to become engaged.

Global Warming Thermometer

Practically everyone has heard of the Kyoto Protocol (ratified by 183 nations as of 2008; expired in 2012), as well as the IPCC and their assessments. But not many people are familiar with the United Nations Framework Convention on Climate Change (UNFCCC), which was signed onto by over 150 nations (including the USA) at the Rio Earth Summit in 1992, and which serves as the basis for all international talks on climate change.

The UNFCCC has been called the centrepiece of global efforts to combat global warming. If heeded, it holds the potential to mitigate the global climate emergency.

The official objective of the UNFCCC is 
" prevent dangerous anthropogenic interference 
with the climate system."

But we have a shocking and very dangerous problem here. Although "dangerous" is clearly defined throughout the Convention (see bolded passages below), the position of all parties is that scientifically it is not.

The position of Annex 1 signatory countries (industrialized nations), the UNFCCC Secretariat, and the IPCC is that "dangerous," in the context of interference with the climate system, is not yet defined. This is one of the barriers that has led to over 20 years of meetings, discussion and debate — rather than action — on global climate change, which has in turn led us to the brink of planetary catastrophe.

Indeed, the 2007 IPCC AR4 and the 2014 IPCC AR5 never mention the word "dangerous," apparently substituting the term "reasons for concern." The IPCC itself does not define a level at which climate change becomes "dangerous."

Present-day Neros diddle while the Earth burns.

Nero Fiddling while global warming

Furthermore, although a literal reading shows that the obligations of signatory nations to prevent climate change dangers are clearly spelled out in the UNFCCC (see bolded passages below), the position of some parties is that they are not.

Without these barriers being resolved, there is little political will to pass serious, binding, remedial (mitigative) measures in the face of the climate denial industry and the huge fossil fuel energy lobby.

This is an impasse crying out for a medical opinion.

Doctors and other health care professionals understand risk and practise risk aversion on a daily basis. The health professions can step up to take on a role as risk educators, as definers of dangerous, and as influencers of political will to avoid climate change dangers — for the sake of all future generations, of all species.

The text of the UN Framework Convention on Climate Change

UNFCCC Website

United Nations Framework Convention on Climate Change — UNFCCC (Excerpted Text)
(Visit the UNFCCC website for the full text) 

Opened for Signature: New York, 9 May 1992 
Entered into Force: 21 March 1994 (Article 23)


For the purposes of this Convention:

  1. "Adverse effects of climate change" means changes in the physical environment or biota resulting from climate change which have significant deleterious effects on the composition, resilience or productivity of natural and managed ecosystems or on the operation of socio-economic systems or on human health and welfare.

  2. "Climate change" means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.

  3. "Climate system" means the totality of the atmosphere, hydrosphere, biosphere and geosphere and their interactions.


The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.


In their actions to achieve the objective of the Convention and to implement its provisions, the Parties shall be guided, inter alia, by the following:

1. The Parties should protect the climate system for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effects thereof.


3. The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures, taking into account that policies and measures to deal with climate change should be cost-effective so as to ensure global benefits at the lowest possible cost. To achieve this, such policies and measures should take into account different socio- economic contexts, be comprehensive, cover all relevant sources, sinks and reservoirs of greenhouse gases and adaptation, and comprise all economic sectors. Efforts to address climate change may be carried out cooperatively by interested Parties. 


1. All Parties, taking into account their common but differentiated responsibilities and their specific national and regional development priorities, objectives and circumstances, shall: 

(c) Promote and cooperate in the development, application and diffusion, including transfer, of technologies, practices and processes that control, reduce or prevent anthropogenic emissions of greenhouse gases not controlled by the Montreal Protocol in all relevant sectors, including the energy, transport, industry, agriculture, forestry and waste management sectors;

(f) Take climate change considerations into account, to the extent feasible, in their relevant social, economic and environmental policies and actions, and employ appropriate methods, for example impact assessments, formulated and determined nationally, with a view to minimizing adverse effects on the economy, on public health and on the quality of the environment, of projects or measures undertaken by them to mitigate or adapt to climate change;

(i) Promote and cooperate in education, training and public awareness related to climate change and encourage the widest participation in this process, including that of non-governmental organizations;

2. The developed country Parties and other Parties included in annex I commit themselves specifically as provided for in the following: 

(a) Each of these Parties shall adopt national policies and take corresponding measures on the mitigation of climate change, by limiting its anthropogenic emissions of greenhouse gases and protecting and enhancing its greenhouse gas sinks and reservoirs. These policies and measures will demonstrate that developed countries are taking the lead in modifying longer-term trends in anthropogenic emissions consistent with the objective of the Convention [....]

(c) Calculations of emissions by sources and removals by sinks of greenhouse gases for the purposes of subparagraph (b) above should take into account the best available scientific knowledge, including of the effective capacity of sinks and the respective contributions of such gases to climate change. [...]

(d) The Conference of the Parties shall, at its first session, review the adequacy of subparagraphs (a) and (b) above. Such review shall be carried out in the light of the best available scientific information and assessment on climate change and its impacts, as well as relevant technical, social and economic information. Based on this review, the Conference of the Parties shall take appropriate action, which may include the adoption of amendments to the commitments in subparagraphs (a) and (b) above.

3. The developed country Parties and other developed Parties included in annex II shall provide new and additional financial resources to meet the agreed full costs incurred by developing country Parties in complying with their obligations under Article 12, paragraph 1. They shall also provide such financial resources, including for the transfer of technology, needed by the developing country Parties to meet the agreed full incremental costs of implementing measures that are covered by paragraph 1 of this Article and that are agreed between a developing country Party and the international entity or entities referred to in Article 11, in accordance with that Article. The implementation of these commitments shall take into account the need for adequacy and predictability in the flow of funds and the importance of appropriate burden sharing among the developed country Parties.

4. The developed country Parties and other developed Parties included in annex II shall also assist the developing country Parties that are particularly vulnerable to the adverse effects of climate change in meeting costs of adaptation to those adverse effects.

5. The developed country Parties and other developed Parties included in annex II shall take all practicable steps to promote, facilitate and finance, as appropriate, the transfer of, or access to, environmentally sound technologies and know-how to other Parties, particularly developing country Parties, to enable them to implement the provisions of the Convention. In this process, the developed country Parties shall support the development and enhancement of endogenous capacities and technologies of developing country Parties. Other Parties and organizations in a position to do so may also assist in facilitating the transfer of such technologies.


8. In the implementation of the commitments in this Article, the Parties shall give full consideration to what actions are necessary under the Convention, including actions related to funding, insurance and the transfer of technology, to meet the specific needs and concerns of developing country Parties arising from the adverse effects of climate change and/or the impact of the implementation of response measures, especially on:

(a) Small island countries;

(b) Countries with low-lying coastal areas;

(c) Countries with arid and semi-arid areas, forested areas and areas liable to forest decay;

(d) Countries with areas prone to natural disasters;

(e) Countries with areas liable to drought and desertification;

(f) Countries with areas of high urban atmospheric pollution;

(g) Countries with areas with fragile ecosystems, including mountainous ecosystems;

(h) Countries whose economies are highly dependent on income generated from the production, processing and export, and/or on consumption of fossil fuels and associated energy-intensive products; and

(i) Land-locked and transit countries.

9. The Parties shall take full account of the specific needs and special situations of the least developed countries in their actions with regard to funding and transfer of technology.


(Visit the UNFCCC webiste for the full text)

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