There’s currently a scientific consensus that humans are the primary cause of the recent warming trend (over the last century or so).
There’s both supporters of that consensus, and those who challenge or debate it.
Below, we’ve summarised some of the points that each of them might make in regards to the consensus (in addition to other lines of support for, or questions about the consensus)
This guide is intended as an exploratory, impartial guide.
Points Supporting The Current Consensus On Climate Change
The following section contains what might be some important information from several articles that may support the consensus.
We’ve paraphrased and summarised this information, along with providing some direct quotes, but, you can view the full information via the URL links in the ‘Sources’ list at the bottom of this guide.
‘The 97% Consensus On Global Warming’ (from skepticalscience.com)
This report references climate change consensus studies from 7 different authors.
They indicate that these authors made two clear conclusions that weigh in favor of supporting the consensus.
The important things to point out here might be:
– There’s 7 studies from different authors
So, there’s multiple studies providing this sample size
– Agreement that ‘humans are responsible for climate change’ ranges between 90% to 100% between publishing climate scientists, with most studies finding 97% consensus.
However, they do mention this does depend on how the expert consensus is measured i.e. this is a variable that may lead to different %’s of consensus when the measurement is changed
– The greater the level of climate science expertise of those surveyed, the higher the level of climate consensus
‘Consensus on consensus: a synthesis of consensus estimates on human-caused global warming’ (from iopscience.iop.org)
The important information from this report might be:
– 6 independent studies by co-authors of this paper indicate that 90%–100% of publishing climate scientists agree that there’s a consensus that humans are causing recent global warming
And these results are consistent with another report which is based on 11,944 abstracts of research papers (where 4014 took a position on the cause of recent global warming)
The finding of the studies might also be consistent with other surveys of climate scientists and peer-reviewed studies
– They do mention though that there is a different conclusion amongst non-experts (like economic geologists and a self-selected group of those who reject the consensus)
But, this might be expected as level of expertise might correlate with level of consensus
How the OISM Petition Project casts doubt on the scientific consensus on climate change (from skepticalscience.com)
This report provides a rebuttal to the Petition Project, which generally rejects the idea we need to reduce or eliminate human caused greenhouse gases.
skepticalscience.com points out that the Petitions Project might have the following flaws:
– The 30,000 scientists and science graduates listed on the OISM petition represents only a tiny fraction (0.3%) of all science graduates
So, a greater % of all scientists and science graduates might need to be included to get a more accurate picture of their complete answer
– Only 39 scientists who specialise in climate science are included in the OISM list
i.e. this is only a small number of scientists with expertise or specialised knowledge
‘The Cook et al. (2013) 97% consensus result is robust’ (from skepticalscience.com)
This report provides commentary or an analysis of the ‘The 97% Consensus On Global Warming’ report
Some important information from this report might be:
– There are National Academies of Science from 33 different countries all endorsing the consensus
This provides a reasonable sample size and diversity
– Dozens of scientific organizations have endorsed the consensus on human-caused global warming
And, The American Association of Petroleum Geologists was the only one to reject the consensus, and they eventually changed to a neutral position when members threatened to not renew their memberships due to its position of climate denial
– Overall, the 97% consensus on human-caused global warming has been found using several different methods in various studies over the past decade
– There’s been various studies quantifying the human contribution to global warming
– The scientific literature is quite clear that humans have caused most of the global surface warming over the past half century
– The 97% consensus is made up only by experts
Attempts to cast doubt on scientific consensus on climate change despite 97% agreement (from skepticalscience.com)
Some may argue that many studies on climate change don’t specifically endorse the consensus position
However, this may simply be because scientists have mostly moved from what’s causing global warming, to discussing specific details to the problem, such as how fast warming is happening, how soon we might reach a certain level of warming, what the exact effects might be in the future, and so on
The 5 characteristics of global warming consensus denial (from skepticalscience.com)
This report identifies what might be 5 common tactics used by those who deny or question climate change in an attempt to challenge or discredit the consensus
A summarised list of those 5 tactics might include cherry picking, using the fake expert strategy, misrepresentation and logical fallacy, impossible expectations of what research can deliver, and proposing conspiracy theories
‘Climate Myths sorted by taxonomy’ (from skepticalscience.com)
skepticalscience.com provides a list of reports addressing different climate myths
Points Challenging The Current Consensus On Climate Change
The following section contains information relating to challenging the scientific consensus about climate change.
It’s a mix of our paraphrased and summarised breakdown/commentary, and also some direct quotes from a fraserinstitute.org report.
You can view the full information in the report via the URL link for fraserinstitute.org in the ‘Sources’ list at the bottom of this guide.
We’ve sorted the information into points that might seem more credible, and points that may seem less credible.
Points Challenging The Consensus That Might Seem More Credible
– The climate change consensus, along with various aspects of the climate change issue, should be expressed or stated in a more specific and detailed way, and be less generalised or broad
There might be hundreds of questions that can be asked about climate change.
These question might get very detailed and nuanced.
Some may indicate that we need to know what precise question about climate change that the consensus is addressing (and that experts are agreeing on). It should be expressed in detail, word for word.
For example, the consensus might be any one of the following statements:
‘… anthropogenic (coming from humans) greenhouse gas emissions (i.e. mainly CO2) from the burning fossil fuels are the primary cause/driver to Earth’s recent Earth warming trend (i.e. the last century or so)’
Or, … there are thousands of studies on climate change, from various sources and organisations, across many countries, that support a consensus that human emissions are the primary cause of the recent climate warming trend
Or, from climate.nasa.gov: ‘Climate-warming trends over the past century are extremely likely due to human activities [as the primary cause]’
Or, from fraserinstitute.org: ‘An Intergovernmental Panel on Climate Change … conclusion [asserts] that most (more than 50 per cent) of the post-1950 global warming is due to human activity, chiefly greenhouse gas emissions and land use change’
Instead, an example of the consensus expressed specifically and in a more detailed way might be ‘X greenhouse gas from mainly X human activities, is the primary cause of the global average warming trend we have measured between X year and Y year, and the full list of specific reasons and evidence for this are A, B, C, D, and so on’.
People may also want a break down of what each phrase in the sentence means.
The same detail might be applied to each aspect of climate change.
– The exact time period of global warming being analysed matters
For example, climate change might generally refer to the warming trend since 1850, or since the Industrial Revolution (the 1950/1960 baseline)
But, Earth is much older than that, and Earth’s climate has varied a lot in that time
Some people may want clear evidence of not just what has caused warming in the last century (or since 1850), but, in all of Earth’s history.
They might argue that the sample size of just since 1850, or the last half century since 1950/1960, isn’t big enough to make definitive conclusions about Earth’s climate.
– Surveys and studies might need more clear transparency about what they involve exactly
Such as how results from surveys and studies are developed or calculated, what data has been used, who exactly was surveyed, what the exact comments from respondents were, and so on
– There might need to be more detail on how survey results were calculated
i.e. specifying or identifying what exactly makes up the ‘97% consensus’
This 97% might only make up the supporting and also the dissenting votes (or those that agree or disagree with the consensus), and not those who are unsure or uncertain.
Some surveyed experts, scientists, or researchers may answer ‘I don’t know’ or ‘I’m split on a decision’, instead of a ‘Yes’ or ‘No’ about agreeing with or disagreeing with a question or statement.
That 97% figure might drop when those who are unsure/uncertain are included
fraserinstitute.org gives three relevant examples of this …
From fraserinstitute.org, one example might be:
[With] The most highly cited paper [that] found [that] 97 per cent of published scientific studies support man-made global warming … Most papers (66 per cent) actually took no position.
Of the remaining 34 per cent, 33 per cent supported at least a weak human contribution to global warming … So divide 33 by 34 and you get 97 per cent, but this is unremarkable since the 33 per cent includes many papers that critique key elements of the IPCC position.
From fraserinstitute.org, another example might be:
In 2012 the American Meteorological Society (AMS) surveyed its 7,000 members, receiving 1,862 responses [and] Of those, only 52% said they think global warming over the 20th century has happened and is mostly man-made (the IPCC position).
The remaining 48% either think it happened but natural causes explain at least half of it, or it didn’t happen, or they don’t know.
Furthermore, 53% agree that there is conflict among AMS members on the question … Not only do about half reject the IPCC conclusion, more than half acknowledge that their profession is split on the issue.
The near 50/50 split among AMS members on the role of greenhouse gases is a much more accurate picture of the [climate change issue, instead of a 97% consensus]
From fraserinstitute.org, another example might be:
The Netherlands Environmental Agency recently published a survey of international climate experts [where] 6550 questionnaires were sent out, and 1868 responses were received, a similar sample and response rate to the AMS survey.
In this case the questions referred only to the post-1950 period [and, the results were that] 66% agreed with the IPCC that global warming has happened and humans are mostly responsible [and] The rest either don’t know or think human influence was not dominant. So again, no 97% consensus behind the IPCC
– There might need to be more detail about what specific comments were about the climate issue from survey participants
Some survey respondents might have had qualifying comments on their survey answer which provides more context, instead of just a ‘yes’ or ‘no’ answer and noting else.
From fraserinstitute.org:
[Regarding a recent slowdown in warming … IPCC and Dutch survey respondents have differed in what they reported they believed has happened, and it might be important to know their exact feedback and comments]
– The methods and processes that surveys use might be either imprecise, or flawed in different ways (in coming up with a balanced conclusion, or a precise scientific truth)
Methods and processes might need to be analysed/scrutinised to make sure this isn’t the case
For example, fraserinstitute.org indicates that:
The most highly cited paper [that] found [that] 97 per cent of published scientific studies support man-made global warming [… has] poor survey methodology, [and that] tabulation is often misrepresented …
– The qualifications and level of expertise of survey participants should be transparent and clear
For example …
Do they have relevant expertise in a climate specific field, or are they just experts that work in a connected field?
What exact core climate change issues are the participants an expert in? Is it relevant to the survey?
From fraserinstitute.org, an example of where this might have been an issue might be:
[The Netherlands Environmental Agency’s survey which involved 6550 questionnaires being sent out] … raises [question] about the level of knowledge of the respondents [because] Although all were described as “climate experts,” a large fraction only work in connected fields such as policy analysis, health and engineering, and may not follow the primary physical science literature.
– Some argue that surveys and other tools are not precise or comprehensive enough to make accurate conclusions about, or form accurate consensus on climate change, which is ultimately a complex scientific and policy issue
Instead, climate change might require factual debates and careful consideration of all facets of the issue, both scientifically and politically.
Some may even claim that the underlying issues of climate change are so complex that it’s unreasonable to expect unanimity in agreeing on certain issues
– Potential climate change solutions such as mitigation and adaptation might come with serious tradeoffs, and/or restructuring of society to consider
Some argue that the potential result of doing nothing to reduce emissions (like reducing fossil fuel use) and address climate change might be catastrophic in the worst case scenario
However, there may also be negative tradeoffs to consider with some proposed solutions
For example, there might be economic costs, loss, or risks to consider when trying to reduce emissions
Different parts of society may also be impacted, like for example where climate studies and publications impact policymakers’ decisions, and people’s everyday actions and lifestyles
The above things may result in significant restructuring of the economy and society
The above might especially be true when solutions are implemented at large scales
Either way – most agree there will be significant future loss and damage from either climate change itself, or from the policies designed to prevent climate change.
– Some aspects of climate change may not have a clear answer
Some people may want a consensus, or a yes or no answer to some aspects of climate change
But, climate change is a complex issue that may not have a clear answer to some aspects
There may also context and nuance needed for some answers, and, some answers may change in the future as we get more information, or our understanding improves
It may also be challenging to try to forecast certain aspects of the climate in the future due to unknowns or variables.
– There may be self interest for some parties in developing certain climate change conclusions, and there may be competing interests for different parties across society
It may benefit some groups or parties commercially, politically, or in other ways, to arrive at a certain conclusion
For example, fossil fuel energy producers may have a competing interest with renewable energy producers and other non fossil fuel energy producers
This consideration shouldn’t be ignored when dealing with an issue of the scale of climate change
Points Challenging The Consensus That Might Seem Less Credible
– Potential cherry picking of organisations and papers
To make their point about how the consensus might be fabricated, Fraser Institute cites the IPCC, the ‘most highly cited paper’ (about the consensus), the AMS, and the NEA
Whether it’s intentional or not, this might be a case of cherry picking, because there are many more researchers and organisations from many more countries that have provided feedback on the consensus than these ones
Refer to the Skeptical Science website for the most comprehensive breakdown of the consensus
– It might be questionable to definitively say that the benefits of pursuing fossil fuels in the future definitely outweigh the climate related costs
Fossil fuels certainly are very important to society at this point in time, and they have a range of uses
So, it might be accurate to say that scaling down their use might come with a range of negative tradeoffs – economically, practically, and so on
However, fossil fuels do have their own pros and cons to consider, and, it may also not be able to be concluded with absolute certainty that the continued use of fossil fuels at the current rate won’t end up in a catastrophic climate event (in the worst case scenario)
How Trustworthy Is Climate Change Funding, Research & Reporting?
Sources
1. https://www.skepticalscience.com/global-warming-scientific-consensus-advanced.htm
2. https://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002
3. https://www.skepticalscience.com/OISM-Petition-Project-intermediate.htm
4. https://skepticalscience.com/97-percent-consensus-robust.htm
5. https://www.skepticalscience.com/klaus-martin-schulte-consensus.htm
6. https://skepticalscience.com/5-characteristics-consensus-denial.html
7. https://skepticalscience.com/argument.php?f=taxonomy
8. https://climate.nasa.gov/scientific-consensus/
9. https://www.fraserinstitute.org/article/putting-con-consensus-not-only-there-no-97-cent-consensus-among-climate-scientists-many
10. http://www.petitionproject.org/index.php
