We predict that the Permafrost Carbon Feedback will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42–88% of the total global land sink.

- Kevin Shaefer, National Snow & Ice Data Center

Just the melting of all the floating ice in the arctic ocean, will add as much heat to the earth, as all the Co2 we put in the atmosphere to date.

- Dr. James Lovelock

A Tipping Point is defined as a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system, forcing it into an entirely different regime. The term “tipping element” describes large-scale components of the Earth system that may pass a tipping point.  Our global climate system is extremely complex and a large number of inter-related subsystems keep the climate stable and within a band of conditions optimal for life on earth. Upsetting any one of these variables can upset the entire climate and changes in any one of these identified tipping points could trigger another one, resulting in a runaway positive feedback loop. To explicitly  identify these tipping points, scientists have now defined the concept of planetary boundaries.

Unfortunately, the dual pressure of population and economic growth continue to create secondary pressures such as global warming, resource depletion and pollution, which inch earth system processes closer and closer to planetary boundaries.


Table of Contents

  1. Safe Limits
  2. Types of Tipping Points
  3. World Clock Monitor of Tipping Point Elements
  4. Current Estimations and Projections of Global Mean Temperature
  5. Temperature Thresholds for Major Tipping Points
  6. Disturbing Research findings of Dr. Kevin Anderson and Alice Bows of Tyndall Centre for Climate Research
  7. Disturbing Research findings of Dr. Ken Caldeira and Damon Matthews of Carnegie Institution
  8. Findings from 2008 National Academy of Science paper Tipping elements in the Earth’s climate system
  9. Specific Tipping Point
  10. James Lovelock’s Warnings


Safe Limits

Setting a safe upper limit to the amount of CO2 in the atmosphere lays at the center of studies to avoid these tipping points. The average concentration of  CO2 in 2009 was 387 parts per million (ppm), with an annual increase of 2 ppm.A target of 450 ppm has been advocated to avoid ‘dangerous’ climate change, and under business as usual the world will reach that target before 2040. Dr. James Hansen, Director of NASA Goddard Institute for Space Studies, has countered that 450 ppm in not sufficient to avoid consequential climate tipping points, and concluded that 350 ppm, roughly the concentration in 1990, is the safe upper limit.2


Types of Tipping Points

The number of tipping points we are already approaching is alarming:

  • Melting will raise sea levels so that less heat is reflected out to space
  • Forests will no longer absorb carbon, but become carbon sources
  • Enormous deposits of methane clathrates held in the mud under the sea under high pressure are released
  • Melting permafrost in the frozen tundra of Northern Canada and Siberia releases vast quantities of methane
  • Drought kills the Amazon forest and we lose a valuable carbon sink
  • Global dimming is the temporary reduction of atmospheric temperature due to pollutants in the air. The benefits of being shielded by global dimming ceases as industrialization comes to a stop to to global warming disruptions
  • Forest fires simulataneously increase the carbon load and eliminate more valuable carbon sinks
  • Increased El Nino ocean warming reduces its capacity to absorb carbon


World Clock monitor of Tipping Point Elements





Fig.1: World Clock with critical Tipping Point Parameters


Current Estimations and Projections of Global Mean Temperature

Global Mean Temperature is the main variable in Climate Change. It is inter-related to a vast network of other climate variables such as GHG or CO2 emissions. In a 2008 study in the Proceedings of the National Academy of Sciences, V. Ramanathan and Y. Feng from Scripps Institution of Oceanography, University of California, San Diego, calculated that greenhouse gas [GHG] emissions as of 2005 have committed the planet to warming of “2.4˚C above the preindustrial surface temperatures,” 3

The 2.4˚C  budget is based upon:

The present (2008) observed temperature increase of 0.76˚C (from pre-industrial levels) is misleading because:

  • Warming of at least another 1˚C is presently being masked by “atmospheric brown clouds” containing cooling particulates released with greenhouse gas emissions and other pollution (commonly called aeresols). As we continue to reduce the pollution creating these clouds, largely for health reasons, we are unmasking the 1˚C temperature increase committed from current emissions.
  • An additional 0.6˚C warming is currently trapped by ocean thermal inertia.

Therefore, the total committed warming is  0.76˚C +  1˚C  + 0.6˚C = 2.36˚C, with more than 50% expected to occur within decades


Fig. 2: Expected Global Mean Temperature Rise as a function of Emission Control Policies (from Climate Interactive)

Figure 2 above reveals what kind of mean global temperatures the planet will experience if  UN climate policy consensus is reached while Fig. 3 below shows where the tipping points are with respect to temperature. Notice that all of them occur within the 2 to 4 °C window The temperature limit of 2°C higher than pre-industrial levels has been discussed as an acceptable target by the UN. Most leading climate scientists, however, now believe that 2°C of warming would pose a substantial risk. This temperature rise has the potential to trigger irreversible changes in those systems include the disappearance of Arctic summer sea-ice, the melting of the Himalayan-Tibetan glaciers and the melting of much of the Greenland ice-sheet.


Temperature Thresholds for Major Tipping Points

Fig. 3: Tipping Points vs. Temperature Threshold Ranges that initiate Tipping, Source: Ramanathan & Feng (2008)


 Fig. 4: Current Global Mean Temperature (Source: www.co2now.org)

Atmospheric CO2 data and trend

 Fig. 5: Current Global CO2 Concentrations (PPM) (Source: www.co2now.org)


Disturbing Research findings of Dr. Kevin Anderson and Alice Bows of Tyndall Centre for Climate Research

Table 1: Peaking Year, Annual Emissions Reduction Rate and Likely Associated Warming above Pre-industrial Levels


In a lecture paper presented to the Royal Society of the Arts “Is it too late to prevent catastrophic climate change?” Clive Hamilton, Charles Sturt Professor of Public Ethics, Centre for Applied Philosophy and Public Ethics at the Australian National University reaches a bleak conclusion about the future. In this paper, Professor Hamilton analyzes conclusions based on the latest research on emission reduction pathways and draws his own conlusions about what this means for the future of humanity.

In particuliar, Hamilton relies on research done by world renowned climatologist Kevin Anderson and Alice Bows from the United Kingdom’s Tyndall Centre for Climate Change Research. Anderson and Bow presented a paper to a meeting of the Royal Society in 2008  in which they analyzed what concentration of CO2 would be in the atmosphere given the world adopted a very aggressive treatment regimen. The analysis is based on a very optimistic assumption that global CO2 emissions will peak in 2020 (although a more realistic date would be 2030) 5

Based on the 2020 peaking assumption, a 3 per cent reduction each year thereafter for developing countries and 6-7 per cent reduction in developed countries, Anderson and Bows concluded that this will not be enough to keep us below a “safe” level of  2°C or 450 ppm. The data analysis showed that an extra 3,000 billion tonnes of greenhouse gases would end up in the atmosphere and levels would far exceed 450ppm. This, in spite of acting promptly and with the most optimistic set of assumptions such as:

  • Ending of deforestation
  • Halving of emissions associated with food production
  • Global emissions peaking in 2020 and then falling by 3 per cent a year for a few decades
Anderson and Bows main conclusion is this:  a catastrophic 650 ppm (or a 4°C rise) will be unavoidable even given the most optimistic UN emission reductions. Looking at Fig. 3 above, you can see that a  4°C rise will exceed almost every Tipping Point. Remembering that each Tipping Point alone can be the cause of a runaway temperature increase. Anderson does not rule out a 6°C rise by the end of the century.

This above calculation was conservative, not taking into account:

  • Non-CO2 emissions from aviation and shipping
  • Global Dimming – aerosols, the tiny particles also included in atmospheric emissions. These particles mask some of the warming otherwise built in to the system and their clean-up of urban air pollution in China and India—through laws requiring use of cleaner fuels, fitting catalytic converters to vehicles and mandating scrubbers on power plants—would bring on the warming more quickly, perhaps as early as 2060
  • Other Tipping Point events such as Greenland Ice Sheets, Arctic Ice or Permafrost and Tundra melting that would dramatically increase warming  and /or release enormous amounts of GHG into the atmosphere

Another interactive display that shows what we can expect is from Google Earth: What a 4°C Earth will look like:


Professor Anderson speaks about his findings here:


This is the conflict confronting him as he measures increasing levels of atmospheric carbon dioxide, plots the corrective measures being taken by the world’s countries, then anticipates the consequences. “As an academic,” he confesses, “I wanted to be told that it was a very good piece of work and that the conclusions were sound. But as a human being, I desperately wanted someone to point out a mistake, and tell me we had got it completely wrong” (The Guardian Weekly, Jan. 01/09).

Anderson’s results were among those used at an emergency conference in Copenhagen in 2009 in which at least 2,500 of the world’s other leading environmental experts believe he has made no mistake and his conclusions are correct. In speaking for the collective concern of his colleagues, Dr. Anderson says, “Scientists have lost patience with carefully constructed messages being lost in the political noise. We are now prepared to stand up and say enough is enough” (The Vancouver Sun, Mar. 13/09).

Hundreds of millions of people would have to move, probably billions. What would be the implications of that? Extended conflict, social disruptions, war essentially, over much of the world for many decades  

- Sir Nicholas Stern, former chief economist for the World Bank


Disturbing Research findings of Dr. Ken Caldeira and Damon Matthews of Carnegie Institution


In the 2008 study Stabilizing Climate requires Near Zero Emissions published in Geophysical Research Letters, climate scientists Ken Caldeira and Damon Matthews used an Earth system model developed at the University of Victoria, Canada to simulate the response of the Earth’s climate to different levels of carbon dioxide emission over the next 500 years. The model includes variables for the flow of heat between the atmosphere and oceans,  the uptake of carbon dioxide by land vegetation as well as other relevant factors in its calculations.

This was the first peer-reviewed study to investigate the levels of carbon dioxide emission required to prevent further warming of the planet. While most discussions have centered around what emission levels would need to get to in order to stabilize greenhouse gases in the atmosphere, a stable concentration does not imply a stable climate. The scientists therefore set out to study the emissions necessary to stabilize climate in the foreseeable future.

Caldeira and Mathews investigated how much climate changes as a result of  individual pulses of  carbon dioxide emissions, simulating 4 different quantities: 50, 200, 500 and 2000 billion tons. and found that each increment of emission leads to another increment of warming. To avoid additional warming, we need to effectively avoid additional emissions.
In the simulations, the level of carbon dioxide in the atmosphere slowly fell only when emissions were reduced to zero. Carbon “sinks” such as the oceans and land vegetation had the capacity to absorb the gas. In an unexpected finding, the model predicted that global temperatures would remain high for at least 500 years after carbon dioxide emissions ceased.
This is similar to the thermal inertia effects within heated metal. Anyone who cooks knows that when an iron skillet is heated, it will retain its heat and keep cooking even after the stove’s heating element has been turned off. In the same way, the heat held in the oceans will keep the climate warm even as the heating effect of greenhouse gases diminishes. The addition of more greenhouse gases, even at lower rates than today will only worsen the situation and keep the global mean temperature high for centuries.

Caldeira holds that if tomorrow we discover that a climate catastrophe was imminent if our planet warmed any further, then the only way to avoid this catastrophe would be to immediately reduce emissions close to zero.

With COP17 over and more years of delay, global carbon dioxide emissions and atmospheric carbon dioxide concentrations will both continue growing at high rates. If we could stabilize atmospheric carbon dioxide concentrations (a highly optimistic scenario) the Earth would continue heating up. To prevent the Earth from heating further, carbon dioxide emissions would, effectively, need to be eliminated completely.

The conclusion? In Caldeira and Mathews own words: We have shown here that stable global temperatures within the next several centuries can be achieved if CO2 emissions are reduced to nearly zero. This means that avoiding future human-induced climate warming may require policies that seek not only to decrease CO2 emissions, but to eliminate them entirely

Eliminating carbon dioxide emissions may seem impossible, but Caldeira believes it is an achievable technological challenge if we can move aggressively and immediately to embrace renewable energy and sustainable technologies and practices in a major way.


Findings from 2008 National Academy of Science paper entitled Tipping elements in the Earth’s climate system

from 2008 National Academy of Science paper entitled Tipping elements in the Earth’s climate system authors: Timothy M. Lenton, Hermann Held, Elmar Kriegler, Jim W. Hall, Wolfgang Lucht , Stefan Rahmstorf and Hans Joachim Schellnhuber


To examine possible tipping points in the earth’s systems, the authors gathered data, reviewed literature and solicited opinions from climate experts on potential tipping elements in the earth’s climate systems.

Table 1 below outlines the most policy-relevant tipping elements that were examined.  The team concluded that:

  • The Greenland ice sheet and Arctic summer ice exhibit the highest sensitivity and the smallest uncertainty
  • The tipping elements in the tropics, the boreal zone, and West Antarctic have a significant amount of uncertainty surrounding them, but that “given their potential sensitivity, constitute candidates for surprising society

Greenland Ice Sheet & Arctic Sea Ice Loss 

  • Significant changes in the Arctic environment could lead to dramatic swings in weather and climate patterns around the planet.
  • Influx of large amounts of freshwater into the northern Atlantic Ocean from a melting Arctic ice cap and the Greenland ice sheet may alter the Atlantic Themohaline Circulation. This circulation brings warm water north from the Caribbean to North Europe.
  • A change is this circulation that might occur in next 100 years if current climate trends are not reversed.3
  • Collapse of one system may trigger collapse of other systems, bringing about disruptive changes over relatively short time periods.4
  • Dr. James Hansen of NASA has warned that the earth’s climate system is reaching dangerous tipping points:  “elements of a ‘perfect storm’, a global cataclysm, are assembled.”
  • “The tipping point for life on the plant will occur when so many interdependent species are lost that ecosystems collapse.”5
Table 1: Policy-relevant potential future tipping elements in the climate system

from 2008 National Academy of Science paper entitled Tipping elements in the Earth’s climate system authors: Timothy M. Lenton, Hermann Held, Elmar Kriegler, Jim W. Hall, Wolfgang Lucht , Stefan Rahmstorf and Hans Joachim Schellnhuber


Numbers given are preliminary and derive from assessments by the experts at the workshop, aggregation of their opinions at the workshop, and review of the literature.


  • Global mean temperature change above present (1980–1999) that corresponds to critical value of control, where this can be meaningfully related to global temperature.
  • § Meaning theory, model results, or paleo-data suggest the existence of a critical threshold but a numerical value is lacking in the literature.
  • Meaning either a corresponding global warming range is not established or global warming is not the only or the dominant forcing.
  • Meaning no subcontinental scale critical threshold could be identified, even though a local geographical threshold may exist.


Specific Tipping Points

Arctic Sea Ice, Permafrost thawing and Methane Hydrate Outgassing

The Arctic is home to a large number of tipping points from Arctic sea ice to permafrost thawing on land to methane hydrates in the shallow Arctic ocean. To explore more, go here.

Biodiversity Loss

A variety of global changes are driving rates of species extinction that greatly outpace background rates in the fossil record. If these trends continue, projections suggest that within 240 years Earth may
face the sixth mass extinction – A global synthesis reveals biodiversity loss as a major driver of ecosystem change, Hooper, DU et al. – Go here to explore more on biodiversity loss.

Greenland Ice Sheets

Extreme Melting on Greenland Ice Sheet, Reports CCNY Team
Oct 13, 2011
According to a new analysis by Dr. Marco Tedesco, director of  the Cryospheric Processes Laboratory and assistant professor in the Department of Earth and Atmospheric Sciences at The City College of New York, the Greenland ice sheet can experience extreme melting even when temperatures don’t hit record highs.  His findings suggest that glaciers could undergo a self-amplifying cycle of melting and warming that would be difficult to halt.

“We are finding that even if you don’t have record-breaking highs, as long as warm temperatures persist you can get record-breaking melting because of positive feedback mechanisms,” said Professor Tedesco. He and graduate student Patrick Alexander arrived before the onset of the melt season and found a near-record loss of snow and ice this year. The extensive melting continued even without last year’s record highs.

Temperatures and an albedo  feedback mechanism accounted for the record losses. A white blanket of snow reflects much of the sun’s energy and thus has a high albedo while bare ice – being darker and absorbing more light and energy – has a lower albedo. Absorbing more energy from the sun means that darker patches warm up faster, like the blacktop of a road in the summer. The more they warm, the faster they melt.

2011 followed 2010, a year with record high temperatures and this may have created more dark ice just below the surface, ready to warm and melt as soon as temperatures begin to rise. This explains why more ice sheet melting can occur even though temperatures did not break records.

Professor Tedesco compares the melting process to a speeding steam locomotive. Higher temperatures act like coal shoveled into the boiler, increasing the pace of melting. In this scenario, “lower albedo is a downhill slope,” he says. The darker surfaces collect more heat. In this situation, even without more coal shoveled into the boiler, as a train heads downhill, it gains speed. In other words, melting accelerates.

Only new falling snow can put the brakes on the process by covering the darker ice in a reflective blanket, Professor Tedesco says. The model showed that this year’s snowfall couldn’t compensate for melting in previous years.  “The process never slowed down as much as it had in the past,” he explained. “The brakes engaged only every now and again.” Worryingly, Dr. Tedesco found this happening not just in the glacier he studied, but all over Greenland.

Global Dimming

Ironically, there is a positive effect of pollution which actually reduces global mean temperature.  Industry has released a huge quantity of aerosol particles that reflect incoming sunlight right around the planet’s northern hemisphere. While CO2 increases temperature, this mixture of exhaust fumes, smoke and dust reduces global warming by reflecting sunlight back into space and shields us from some of the sun’s radiation.

This phenomenon, global dimming can reduce heating locally by between 2-3°C. Thus, our constant aeresol pollution is actually necessary to maintain this shield that prevents the true atmospheric temperature from appearing. Hence we continue business as usual with a false sense of security. The trouble is, this global dimming effect is temporary. The shield could dissappear in a matter of days of there is a major disruption of fossil fuel pollutants entering the atmosphere, allowing temperatures to suddenly spike. In fact, the world experienced such an event recently when all airplanes were grounded for three days after the September 11 attack on the Twin Towers. Due to loss of airplane contrials, scientists found that temperatures then rose by 1.3°C .

All that is required is one major tipping point that would cause a severe industrial downturn. The slowdown of manufacturing would stop the constant flow of aerosols into the atmosphere, the shield would be gone and we would be exposed to the full effect of the greenhouse effect.

James Lovelock, the father of the Gaia Theory said, “we are in a fool’s paradise, accidentally kept cool by smoke.”  Lovelock wrote The Revenge of Gaia and warned in The Independent that the world has already passed the point of no return for climate change, and that civilisation as we know it is now unlikely to survive. Lovelock warned that we are in a Catch 22 situation…..our current efforts to slow down global warming cannot succeed because significant reductions in CO2 emissions would lead to global dimming.


James Lovelock’s Warnings

Lovelock is famous in the press for his dire warnings. He wrote “Before this century is over, billions of us will die, and the few breeding pairs of people that survive will be in the Arctic where the climate may remain tolerable.”

The Revenge of Gaia

In Lovelock’s 2006 book, he argues that the lack of respect humans have had for Gaia, through the damage done to rainforests and reduction in biodiversity is interfering with the planet’s natural feedback loops to control CO2 emissions, possibly leading to positive feedback runaway warming.

Warming of the oceans is extending the oceanic thermocline layer of tropical oceans into cold Arctic and Anarctic waters which has the result of preventing the rise of oceanic nutrients into the surface waters and eliminating algal blooms on which oceanic foodchains depend.

Lovelock predicts that the reduction of the 2 major lungs of the earth, the phytoplankton in the ocean and the forests of the land will render most of the earth uninhabitable for humans and other life-forms by the middle of this century, with a massive desertification.

The Vanishing Face of Gaia

In this book, Lovelook rejects scientific modelling that disagrees with the scientific findings that sea levels are rising faster, and Arctic ice is melting faster, than the models predict and he suggests that we may already be beyond the tipping point of terrestrial climate into a permanently hot state. He expects that humanity itself may not survive. He expects the change to be comparable in magnitude to the that encountered in the Paleocene-Eocene Thermal Maximum when atmospheric concentration of CO2 was 450 ppm. During that time, the Arctic ocean was 23 °C while the rest of the world was mostly scrub and desert.

Climate and mass human mortality

In the January 2006 Independent newspaper, Lovelock argues that  “billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable” by the end of the 21st century.

He has been quoted in the Guardian newspaper that 80% of humans will perish by 2100 AD, and this climate change will last 100,000 years.

According to Lovelock, by 2040, global warming, in the form of floods, drought and famine will kill many billions of people.  “The people of Southern Europe, as well as South-East Asia, will be fighting their way into countries such as Canada, Australia and Britain” said Lovelock.

He further predicts, the average temperature in temperate regions will increase by as much as 8°C and by up to 5°C in the tropics, leaving much of the world’s land uninhabitable and unsuitable for farming, with northerly migrations and new cities created in the Arctic. He predicts much of Europe will become uninhabitable having turned to desert and Britain will become Europe’s “life-raft” due to its stable temperature caused by being surrounded by the ocean. He suggests that “we have to keep in mind the awesome pace of change and realise how little time is left to act, and then each community and nation must find the best use of the resources they have to sustain civilisation for as long as they can”.

In a September 2007 address to the World Nuclear Association’s Annual Symposium, in light of new data he said that climate change would stabilise and prove survivable, and that the Earth itself is in “no danger” because it would stabilise in a new state. He did not rule out the possibility, however, of mass species migration to areas hospital to life.

In an interview in the March 2010 edition of the Guardian newspaper, he said that democracy might have to be “put on hold” to prevent climate change


“The great climate science centres around the world are more than well aware how weak their science is. If you talk to them privately they’re scared stiff of the fact that they don’t really know what the clouds and the aerosols are doing…We do need scepticism about the predictions about what will happen to the climate in 50 years, or whatever. It’s almost naive, scientifically speaking, to think we can give relatively accurate predictions for future climate. There are so many unknowns that it’s wrong to do it.”


Geoengineering proposal

In September 2007, Lovelock and Chris Rapley  unveiled a plan to construct a global network of ocean pumps to pump water up from below the thermocline to “fertilize algae in the surface waters and encourage them to bloom”.  The basic idea was to accelerate the transfer of carbon dioxide from the atmosphere to the ocean by increasing primary production and increasing the export of CO2 to the deep ocean. A scheme similar to that proposed by Lovelock and Rapley is already being independently developed by a commercial company as well as promoted by other scientists such as Dr. William Calvin.


1. 2008NOAA. Trends in Atmospheric Carbon Dioxide – Mauna Loa. June 2009

2. A. Revkin. Back to 1988 on CO2, Says NASA’s Hansen. NY Times: Dot Earth. 19 March 2008

3. V. Ramanathan and Y. Feng,On avoiding dangerous anthropogenic interference with the climate system: Formidable challenges ahead, 105 PROC. OF THE NAT’L ACAD. OF SCI. 38, 14245 (23 September 2008).

4. Kevin Anderson and Alice Bows, ‘Reframing the climate change challenge in light of post-2000 emission trends’, Philosophical Transactions of the Royal Society, The Royal Society,

5. Hare et al., ‘Emission reductions by the USA in 2020 and the risk of exceeding 2°C warming’.

6.  Lenton et al. Tipping elements in the Earth’s climate system at 1788-1790

7.  Mike Bettwy, Changes in the Arctic: Consequences for the World, Goddard Space Flight Center, updated February 23, 2008