Climate Change/Global Warming

Monday, Mar 15, 2010

Almost all scientists already agree on the science. An article in the PNAS, journal of the US National Academy of Sciences, last year found that 97 per cent of actively publishing climate scientists believe man-made climate change is happening. Nonetheless, the world hasn’t acted... what most people believe about climate change has little to do with science. After all, hardly any layperson understands it. Rather, people’s beliefs about climate change follow from their beliefs about the world.

American sceptics, for instance, are disproportionately likely to be conservative white males, say the sociologists Aaron McCright and Riley Dunlap. Conservative white males don’t like governments interfering with business. They don’t like global co-operation. Nothing will convince them that we need global co-operation to interfere with business and tackle climate change, especially not if Al Gore says so.

Conversely, liberals who do like global co-operation and interfering with business are going to believe in climate change, even though hardly any of them understand the science either. “Climate change has joined gun control, taxes and abortion as a form of social identity marker,” writes Matthew Nisbet, social scientist at American University in Washington. In this debate, and not just in the US, almost nobody is open to persuasion.

The squabble also creates a one-dimensional argument about climate change: do you believe it’s real or not? I’ve found to my cost that many people can only read articles about climate change as statements of either belief or scepticism. This obscures better questions, such as what exactly we should do about climate change.

The United Nations Intergovernmental Panel on Climate Change (IPCC) is considered the world authority on climate change science (the "consensus"). The IPCC "does not conduct new research. Instead, its mandate is to make policy-relevant—as opposed to policy-prescriptive—assessments of the existing worldwide literature on the scientific, technical and socio-economic aspects of climate change" [].

The latest IPCC report in 2007 concludes: the global climate is warming, many natural systems are affected by this warming, global greenhouse gases due to human activities have grown by 70% since 1974, most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations (anthropogenic effects are those caused by the activities of human beings), continued emissions will induce many changes in the 21st century that are very likely to be greater than those in the 20th century, warming could lead to altered frequencies and intensities of extreme weather, even if greenhouse gases were stabilized anthropogenic warming could continue for centuries, and that anthropogenic warming could lead to abrupt and irreversible effects [].

The 2007 IPCC predictions for future climate change:

Two key points emerge from Figure 10.28. For the projected short-term warming (i) there is more agreement among models and methods (narrow width of the PDFs) compared to later in the century (wider PDFs), and (ii) the warming is similar across different scenarios, compared to later in the century where the choice of scenario significantly affects the projections. These conclusions are consistent with the results obtained with SCMs (Section 10.5.3).


In sum, probabilistic estimates of uncertainties for the next few decades seem robust across a variety of models and methods, while results for the end of the century depend on the assumptions made.

Intergovernmental Panel on Climate Change (IPCC), Historical Overview of Climate Change Science, Pages 808-809, 2007,

When human numbers increased to a certain level and the accumulation of waste was recognised as a health or pollution problem, rules and technologies were established to manage waste disposal. A contemporary example of globally enforced regulation is the Montreal Protocol, where the international community in 1987 agreed to act on scientific evidence that certain industrial gases can lead to dangerous depletion of the Earth’s ozone layer.

In all of these cases, control was only established when there was the general acceptance in society that a continued state of non-regulation would lead to unacceptable costs. Thus, the history of humanity’s relationship with the environment shows that when society learns that a certain practice may jeopardise the well-being of its members, rules, regulations, and other strategies are established to control the offending practice.

The scientific evidence today overwhelmingly indicates that allowing the emission of greenhouse gases from human activities to continue unchecked constitutes a significant threat to the well-being and continued development of contemporary society. The knowledge that human activities are influencing the climate gives contemporary society the responsibility to act. It necessitates redefinition of humanity’s relationship with the Earth and - for the sake of the well-being of society – it requires management of those human activities that interfere with the climate. To support development of effective responses, however, this knowledge should be widely disseminated outside of the scientific community. The purpose of this report is to communicate to a broad range of audiences the research community’s most up-to-date understanding of climate change, its implications, and the actions needed to deal with it effectively.


The climate is largely controlled by the flows of heat entering and leaving the planet and the storage of heat in the various compartments of the Earth System - ocean, land, atmosphere, snow/ice. This heat ultimately comes from the sun. Only a very small amount of the heat is stored in the atmosphere (Figure 2); by far the largest amount of heat stored at the Earth’s surface is found in the ocean. The heat flux into the ocean proceeds more slowly than into the atmosphere. However, given that the ocean stores so much heat, a change in ocean temperature, which reflects a change in the amount of heat stored in the ocean, is a better indicator of change in the climate than changes in air temperature.

Figure 3 shows the trend in surface air temperature in recent decades. 2008 was comparatively cooler than the immediately preceding years, primarily because there was a minimum in the cycle of the sun’s magnetic activity (sun spot cycle) and a La Niña event in 2007/2008. Nevertheless, the long-term trend of increasing temperature is clear and the trajectory of atmospheric temperature at the Earth’s surface is proceeding within the range of IPCC projections.


The evidence that human activities are changing the fundamental conditions for life on Earth is overwhelming, and the challenges presented by these changes are daunting. Postponing action will only increase the risks to future generations. While no single meeting can transform our society to one living within the climate change boundary, the United Nations Climate Change Conference, COP15, to be held in December 2009 offers a unique and timely opportunity to start such a transformative journey.

Synthesis Report from Climate Change: Global Risks, Challenges & Decisions, Copenhagen, March, 2009, University of Copenhagen,

No one argues that the Earth is not warming, but some climate scientists do argue that the warming is caused by humans (instead they argue it is natural variability with a similar period called the Medieval Warm Period which actually had beneficial effects for crop output, etc.), and others argue that governments may not be the best solution to the problem if it is a problem. Dr. Roy Spencer, a climatologist who formerly worked for NASA in their temperature monitoring group, summarizes this as follows (he is currently funded 100% by the government, not by private interests):

“Global warming” refers to the global-average temperature increase that has been observed over the last one hundred years or more. But to many politicians and the public, the term carries the implication that mankind is responsible for that warming. This website describes evidence from my group’s government-funded research that suggests global warming is mostly natural, and that the climate system is quite insensitive to humanity’s greenhouse gas emissions and aerosol pollution.

Believe it or not, very little research has ever been funded to search for natural mechanisms of warming…it has simply been assumed that global warming is manmade...

The ‘consensus’ of opinion is that the Earth’s climate sensitivity is quite high, and so warming of about 0.25 deg. C to 0.5 deg. C (about 0.5 deg. F to 0.9 deg. F) every 10 years can be expected for as long as mankind continues to use fossil fuels as our primary source of energy...

You would think that we’d know the Earth’s ‘climate sensitivity’ by now, but it has been surprisingly difficult to determine. How atmospheric processes like clouds and precipitation systems respond to warming is critical, as they are either amplifying the warming, or reducing it. This website currently concentrates on the response of clouds to warming, an issue which I am now convinced the scientific community has totally misinterpreted when they have measured natural, year-to-year fluctuations in the climate system. As a result of that confusion, they have the mistaken belief that climate sensitivity is high, when in fact the satellite evidence suggests climate sensitivity is low...

The case for natural climate change I also present an analysis of the Pacific Decadal Oscillation which shows that most climate change might well be the result of….the climate system itself! Because small, chaotic fluctuations in atmospheric and oceanic circulation systems can cause small changes in global average cloudiness, this is all that is necessary to cause climate change. You don’t need the sun, or any other ‘external’ influence (although these are also possible…but for now I’ll let others work on that). It is simply what the climate system does.

Global Warming, Dr. Roy Spencer,

Intellectual Ventures:

Spencer's FAQ:


I was a lead author of two chapters in AR2's Working Group 3 report (1995), convening lead author in the Special Report on Regional Impacts published in 2001 (Working Group 2), contributing author of one chapter in AR3's Working Group 1 report (2001), lead author of one chapter in AR3's Working Group 2 report (2001), and contributing author of one chapter in AR4's Working Group 2 report (2007).

The IPCC is a victim of its own success. Policy makers trust the IPCC reports as neutral and authoritative assessments of climate research. Therefore, people with a political agenda have tried to influence the IPCC. Such attempts were largely in vain in AR2 and AR3, but this is not true for AR4. Working Group 2 systematically portrays climate change as a bigger problem than is scientifically acceptable. Working Group 3 systematically portrays climate policy as easier and cheaper than can be responsibly concluded based on academic research. These biases can be found in the chapters, the technical summaries, the summaries for policy makers, and the synthesis report.

Richard Tol's Draft Submission to IAC IPCC Review, May 5, 2010,

Many scientists also argue that there are many mistakes in the IPCC report and process which are politically motivated and also put into question the fact that it is a "gold standard" of scientific quality. The IPCC has admitted to some of those mistakes (e.g. Himalayan glaciers) but stands by its major conclusions. Some critiques: