Climate Change: A Primer

Here’s a quick primer on climate change, discussing the data, organizations, consensus, and other relevant information and resources to understand what climate change is, and why it matters.

What is Global Warming/Climate Change?

There are some great resources that breakdown Global Warming, or Climate Change effectively.

The New Mexico Solar Energy Association has a decent primer.

Global Warming is the increase of Earth’s average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect.

The Department of Ecology for the State of Washington gives us this:

Climate is usually defined as the “average weather” in a place. It includes patterns of temperature, precipitation (rain or snow), humidity, wind and seasons. Climate patterns play a fundamental role in shaping natural ecosystems, and the human economies and cultures that depend on them. But the climate we’ve come to expect is not what it used to be, because the past is no longer a reliable predictor of the future. Our climate is rapidly changing with disruptive impacts, and that change is progressing faster than any seen in the last 2,000 years.

What are the effects of climate change?

The Intergovernmental Panel on Climate Change has put together some fantastic reports on the topic.

First, we’ll look at how they put together their data.

The Assessment Reports and Special Reports produced by the Intergovernmental Panel on Climate Change (IPCC) cover a wide range of disciplines in fulfilling the IPCC’s mandate of assessing scientific, technological and socio-economic information in order to provide policymakers with a clear view of the current state of scientific knowledge relevant to climate change.

The IPCC does not conduct its own research, run models or make measurements of climate or weather phenomena. Its role is to assess the scientific, technical and socio-economic literature relevant to understanding climate change, its impacts and future risks, and options for adaptation and mitigation. Author teams critically assess all such information from any source that is to be included in the report1.

Author teams use calibrated uncertainty language to express a level of confidence in findings based on the strength of the scientific and technical evidence and the level of agreement in the scientific, technical and socio-economic literature2.

At the beginning of the assessment process, each IPCC Working Group sets cut-off dates by which time literature has to be accepted for publication by scientific journals, if it is to be included in the current assessment. Cut-off dates ensure the assessment is as up to date as is practical while ensuring that author teams have sufficient time to fully evaluate all literature included in the assessment. For AR5 the cut-off dates were set so that literature has to be accepted for publication approximately two-three months before completion of the final draft.

Like other scientific publications, IPCC reports refer to cited material in the text with the full citations listed at the end of the relevant chapter so that readers can check the original sources. Copies of material that is cited in IPCC report drafts but not widely available are made available to reviewers upon request during the review period.

In the assessment process, emphasis is placed on the evaluation of all cited literature and of its sources. Contributions to IPCC reports take full advantage of peer-reviewed3 and internationally available literature. Sources other than scientific journals also provide crucial information for a comprehensive assessment. Examples include reports from governments, industry and research institutions, international and other organizations, and conference proceedings. Information about certain experiences and practices in mitigation and adaptation activities in particular may be found in sources other than traditional scientific and technical journals. Such materials may utilize a wide range of quality-assurance mechanisms, including but not limited to formal peer review. Author teams using literature of this kind have a special responsibility to ensure its quality and validity.

The number of sources cited in the Fifth Assessment Report will total many thousands. This is an indication of the extensive literature base on which IPCC reports and their conclusions are built.

The first report is The Physical Science Basis.

Human activities are continuing to affect the Earth’s energy budget by changing the emissions and resulting atmospheric concentrations of radiatively important gases and aerosols and by changing land surface properties. Previous assessments have already shown through multiple lines of evidence that the climate is changing across our planet, largely as a result of human activities. The most compelling evidence of climate change derives from observations of the atmosphere, land, oceans and cryosphere. Unequivocal evidence from in situ observations and ice core records shows that the atmospheric concentrations of important greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2)) have increased over the last few centuries.

The full report can be read here.

The second report is Impacts, Adaptation, and Vulnerability.

Human interference with the climate system is occurring. [WGI AR5 2.2, 6.3, 10.3–6, 10.9] Climate change poses risks for human and natural systems (Figure TS.1). The assessment of impacts, adaptation, and vulnerability in the Working Group II contribution to the IPCC’s Fifth Assessment Report (WGII AR5) evaluates how patterns of risks and potential benefits are shifting due to climate change and how risks can be reduced through mitigation and adaptation. It recognizes that risks of climate change will vary across regions and populations, through space and time, dependent on myriad factors including the extent of mitigation and adaptation.

Read the full report here.

The third report is Mitigation of Climate Change.

‘Mitigation’, in the context of climate change, is a human intervention to reduce the sources or enhance the sinks of greenhouse gases (GHGs). One of the central messages from Working Groups I and II of the Intergovernmental Panel on Climate Change (IPCC) is that the consequences of unchecked climate change for humans and natural ecosystems are already apparent and increasing. The most vulnerable systems are already experiencing adverse effects. Past emissions have already put the planet on a track for substantial further changes in climate, and while there are many uncertainties in factors such as the sensitivity of the climate system many scenarios lead to substantial climate impacts, including direct harms to human and ecological well‐being that exceed the ability of those systems to adapt fully.

The full report is found here.

Note that these three reports are long, and incredibly detailed, delving deep into the science of the subject.

The World Health Organization (WHO) has an excellent summary available discussing Climate Change and human health, which discusses information from the IPCC reports.

In the early 1990s there was little awareness of the health risks posed by global climate change. This reflected a general lack of understanding of how the disruption of biophysical and ecological systems might affect the longer-term wellbeing and health of populations. There was little awareness among natural scientists that changes in their particular objects of study — climatic conditions, biodiversity stocks, ecosystem productivity, and so on — were of potential importance to human health. Indeed, this was well reflected in the meagre reference to health risks in the first major report of the UN’s Intergovernmental Panel on Climate Change (IPCC), published in 1991.

Subsequently, the situation has changed. The IPCC Second Assessment Report (1996) devoted a full chapter to the potential risks to health. The Third Assessment Report (2001) did likewise, this time including discussion of some early evidence of actual health impacts, along with assessing potential future health effects. That report also highlighted the anticipated health impacts by major geographic region.

The US Climate Change Science Program (CCSP) has also released a report discussing the effects on agriculture, which can be very far reaching and detrimental.

This report provides assessment of the effects of climate change on U.S. agriculture, land resources, water resources, and biodiversity. It is one of a series of 21 Synthesis and Assessment Products (SAP) that are being produced under the auspices of the U.S. Climate Change Science Program (CCSP).

What does a scientific consensus on a subject mean?

There’s often talk of a scientific consensus on climate change. What does this mean?

First off, it does not mean a 100% agreement of all scientists, as is often a popular myth. First, you need to look at the relevant fields of science involved. In this case, climate scientists. Then, you look at the agreement between climate scientists.

For this, NASA’s climate desk gives us a good report, well cited, and listing scientific organizations as well.

Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities,1and most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources.


Then, you look to see if the scientific literature on the subject disagrees with the stated consensus. A paper on IOP Science demonstrates this pretty well.

We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. In a second phase of this study, we invited authors to rate their own papers. Compared to abstract ratings, a smaller percentage of self-rated papers expressed no position on AGW (35.5%). Among self-rated papers expressing a position on AGW, 97.2% endorsed the consensus. For both abstract ratings and authors’ self-ratings, the percentage of endorsements among papers expressing a position on AGW marginally increased over time. Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research.

Now, note that the literature doesn’t necessarily need to be overt. As stated, 66.4% expressed no opinion, as they focused on data. Only 0.7%, however, expressed a disagreement with the stated consensus, which is what we’re looking at here. Among those that express an opinion on climate change, 97.1% of those endorsed the consensus that humans are causing it. That’s essential.

The full article breaks down the numbers and data pretty well.

Does this mean that some scientists don’t speak out against the consensus? No, it does not. That’s where you get people like Roy Spencer, who is often trotted out. There’s actually a group of scientists who have signed a petition against the consensus, and these are often cited. You hear often how 31,000 scientists don’t agree that the evidence is there.

Let’s unpack this a bit.

First, you see that many are meteorologists, not climate scientists. Day to day weather, and global climate trends, are vastly different fields. Assuming that meteorologists have the expertise and training to understand global climate models and trends would be a poor assumption.

Of the 31,000 signers, only 9,029 hold a PhD.

3,805 are trained “…in specialties directly related to the physical environment of the Earth and the past and current phenomena that affect that environment.” As they put it.

Of those, only 39 are climatologists.

Our friends over at Skeptical Science, a fantastic site dedicated to discussing climate change in a way that anyone can understand have does a good breakdown regarding the backlash over the consensus study. Once the Wall Street Journal put up their somewhat loaded article, Skeptical Science published this.

Read on skepticalscience.​com

What about the politics?

Unfortunately, climate change is incredibly heated and polarized, politically. Much of this has to do with the financial aspects of combating it, but it’s caused large problems in getting the funding and public support to address these issues.

Ecology and Society addresses policy issued pretty effectively in their report The role of knowledge and power inThe long-term character of climate change and the high costs of adaptation measures, in combination with their uncertain effects, turn climate adaptation governance into a torturous process. We systematically review the literature on climate adaptation governance to analyze the scholarly understanding of these complexities. Building on governance literature about long-term and complex policy problems, we develop a conceptual matrix based on the dimensions knowledge and power to systematically study the peer-reviewed literature on climate adaptation governance. We find that about a quarter of the reviewed journal articles do not address the knowledge or power dimension of the governance of climate change adaptation, about half of the articles discuss either the knowledge or the power dimension, and another quarter discuss both knowledge and power. The articles that do address both knowledge and power (1) conceptualize the governance of climate adaptation mainly as a complex system of regulatory frameworks and technical knowledge, (2) assume that regulatory systems can be easily adapted to new knowledge, (3) pay little attention to fluid or unorganized forms of power, e.g., negotiation, and knowledge, e.g., learning, and (4) largely neglect the interplay between the two. We argue that more research on this interplay is needed, and we discuss how puzzling and powering are a promising pair of concepts to study this. climate change adaptation governance: a systematic literature review.

You can also find a breakdown of Climate Change Denial Books and Conservative Think Tanks put out by Sage.

The conservative movement and especially its think tanks play a critical role in denying the reality and significance of anthropogenic global warming (AGW), especially by manufacturing uncertainty over climate science. Books denying AGW are a crucial means of attacking climate science and scientists, and we examine the links between conservative think tanks (CTTs) and 108 climate change denial books published through 2010. We find a strong link, albeit noticeably weaker for the growing number of self-published denial books. We also examine the national origins of the books and the academic backgrounds of their authors or editors, finding that with the help of American CTTs climate change denial has spread to several other nations and that an increasing portion of denial books are produced by individuals with no scientific training. It appears that at least 90% of denial books do not undergo peer review, allowing authors or editors to recycle scientifically unfounded claims that are then amplified by the conservative movement, media, and political elites.

Climate Change Denial Books and Conservative Think Tanks: Exploring the Connection

The conservative movement and especially its think tanks play a critical role in denying the…Read on ncbi.​nlm.​nih.​gov

In the end, however, what should matter most is the science, and not the politics. It doesn’t matter what political alignment you are. Climate change matters to everyone, and affects everyone.

I hope this primer helps you to understand what climate change is and why it matters. I encourage you to really delve into the resources provided to learn as much as you can about climate change, and avoid the political rhetoric completely. Stick with the science. Stick with the evidence.

Further Reading

The National Center for Science Education

The National Center for Science Education (NCSE) is a not-for-profit, membership organization providing information and resources for schools, parents, and concerned citizens working to keep evolution and climate science in public school science education. We educate the press and public about the scientific and educational aspects of controversies surrounding the teaching of evolution and climate change, and supply needed information and advice to defend good science education at local, state, and national levels. Our 5000 members are scientists, teachers, clergy, and citizens with diverse religious and political affiliations.

The EPA: Climate Change

Our Earth is warming. Earth’s average temperature has risen by 1.4°F over the past century, and is projected to rise another 2 to 11.5°F over the next hundred years. Small changes in the average temperature of the planet can translate to large and potentially dangerous shifts in climate and weather.

Center for Climate and Energy Solutions

At C2ES, we believe that ensuring safe, reliable, affordable energy — while protecting the global climate — is a paramount challenge of the 21st century. We see signs of progress around the world. But far greater effort is needed if we are to keep these challenges from becoming true crises. Now more than ever, we need committed voices with the expertise to cut through complexity and craft innovative solutions; the independence to separate fact from fiction; and the credibility to work with all sides to build common ground.

Read on c2es.​org

US Climate Action Network

Founded in 1989, USCAN fosters and facilitates collaborative efforts to share information, coordinate activities, and develop strategies across diverse organizations and constituencies.

The network spans an array of perspectives and approaches. USCAN members are united by their common goals to reduce US greenhouse gas emissions, to increase climate resiliency, to inspire the United States’ positive leadership in international forums to secure equitable, effective climate policies, and to support on-the-ground implementation of climate solutions.

Center for Clean Air Policy

Since 1985, the Center for Clean Air Policy (CCAP) has been a recognized world leader in climate and air quality policy and is the only independent, nonprofit think tank working exclusively on those issues at the local, U.S. national and international levels. Headquartered in Washington, D.C., CCAP helps policy-makers around the world develop, promote and implement innovative, market-based solutions to major climate, air quality and energy problems that balance both environmental and economic interests.




Philosopher, science communicator, and social justice bard.

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The Vexed Philosopher

Philosopher, science communicator, and social justice bard.

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