Five Climate Myths Debunked

The Conversation, 2019

The science of climate change is more than 150 years old and it is probably the most tested area of modern science. However the energy industry, political lobbyists and others have spent the last 30 years sowing doubt about the science where none really exists. The latest estimate is that the world’s five largest publicly-owned oil and gas companies spend about US$200m each year on lobbying to control, delay or block binding climate-motivated policy.

This organised and orchestrated climate change science denial has contributed to the lack of progress in reducing global green house gas (GHG) emissions – to the point that we are facing a global climate emergency. And when climate change deniers use certain myths – at best fake news and at worse straight lies – to undermine the science of climate change, ordinary people can find it hard to see through the fog. Here are five commonly used myths and the real science that debunks them.

1. Climate change is just part of the natural cycle

The climate of the Earth has always changed, but the study of palaeoclimatology or “past climates” shows us that the changes in the last 150 years – since the start of the industrial revolution – have been exceptional and cannot be natural. Modelling results suggest that future predicted warming could be unprecedented compared to the previous 5m years.

Global temperatures for the last 65m years and possible future global warming depending on the amount of greenhouse gases we emit. Burke et al (2018)

The “natural changes” argument is supplemented with the story that the Earth’s climate is just recovering from the cooler temperatures of the Little Ice Age (1300-1850AD) and that temperatures today are really the same as the Medieval Warm Period (900–1300AD). The problem is that both the Little Ice Age and the Medieval Warming period were not global but regional changes in climate affecting north-west Europe, eastern America, Greenland and Iceland.

A study using 700 climate records showed that, over the last 2,000 years, the only time the climate all around the World has changed at the same time and in the same direction has been in the last 150 years, when over 98% of the surface of the planet has warmed.

2. Changes are due to sunspots/galactic cosmic rays

Sunspots are storms on the sun’s surface that come with intense magnetic activity and can be accompanied by solar flares. These sunspots do have the power to modify the climate on Earth. But scientists using sensors on satellites have been recording the amount of the sun’s energy hitting Earth since 1978 and there has been no upward trend. So they cannot be the cause of the recent global warming.

A comparison of global surface temperature changes (red line) and the sun’s energy received by the Earth (yellow line) in watts (units of energy) per square metre since 1880. NASACC BY

Galactic cosmic rays (GCRs) are high-energy radiation that originates outside our solar system and may even be from distant galaxies. It has been suggested that they may help to seed or “make” clouds. So reduced GCRs hitting the Earth would mean fewer clouds, which would reflect less sunlight back into space and so cause Earth to warm.

But there are two problems with this idea. First, the scientific evidence shows that GCRs are not very effective at seeding clouds. And second, over the last 50 years, the amount of GCRs have actually increased, hitting record levels in recent years. If this idea were correct, GCRs should be cooling the Earth, which they aren’t.

3. CO₂ is a small part of the atmosphere – it can’t have a large heating affect

Eunice Newton Foote’s paper, Circumstances Affecting the Heat of the Sun’s Rays, American Journal of Science, 1857.

This is an attempt to play a classic common-sense card but is completely wrong. In 1856, American scientist Eunice Newton Foote conducted an experiment with an air pump, two glass cylinders and four thermometers. It showed that a cylinder containing carbon dioxide and placed in the sun trapped more heat and stayed warmer longer than a cylinder with normal air. Scientists have repeated these experiments in the laboratory and in the atmosphere, demonstrating again and again the greenhouse effect of carbon dioxide.

As for the “common sense” scale argument that a very small part of something can’t have much of an effect on it, it only takes 0.1 grams of cyanide to kill an adult, which is about 0.0001% of your body weight. Compare this with carbon dioxide, which currently makes up 0.04% of the atmosphere and is a strong greenhouse gas. Meanwhile, nitrogen makes up 78% of the atmosphere and yet is highly unreactive.

4. Scientists manipulate all data sets to show a warming trend

This is not true and a simplistic device used to attack the credibility of climate scientists. It would require a conspiracy covering thousands of scientists in more than a 100 countries to reach the scale required to do this.

Scientists do correct and validate data all the time. For example we have to correct historic temperature records as how they were measured has changed. Between 1856 and 1941, most sea temperatures were measured using seawater hoisted on deck in a bucket. Even this was not consistent as there was a shift from wooden to canvas buckets and from sailing ships to steamships, which altered the height of the ship’s deck – and these changes in turn altered the amount of cooling caused by evaporation as the bucket was hoisted onto deck. Since 1941, most measurements have been made at the ship’s engine water intakes, so there’s no cooling from evaporation to account for.

We must also take account that many towns and cities have expanded and so that meteorological stations that were in rural areas are now in urban areas which are usually significantly warmer than the surrounding countryside.

If we didn’t make these changes to the original measurements, then Earth’s warming over the last 150 years would have appeared to be even greater than the change that has actually been observed, which is now about 1˚C of global warming.

Reconstruction of global temperatures from 1880 to 2018 by five independent international groups of scientists. NASACC BY

5. Climate models are unreliable and too sensitive to carbon dioxide

This is incorrect and misunderstands how models work. It is a way of downplaying the seriousness of future climate change. There is a huge range of climate models, from those aimed at specific mechanisms such as the understanding of clouds, to general circulation models (GCMs) that are used to predict the future climate of our planet.

There are over 20 major international centres where teams of some of smartest people in the world have built and run GCMs containing millions of lines of code representing the very latest understanding of the climate system. These models are continually tested against historic and palaeoclimate data as well as individual climate events such as large volcanic eruptions to make sure they reconstruct the climate, which they do extremely well.

Model reconstruction of global temperature since 1970, average of the models in black with model range in grey compared to observational temperature records from NASA, NOAA, HadCRUT, Cowtan and Way, and Berkeley Earth. Carbon BriefCC BY

No single model should ever be considered correct as they represent a very complex global climate system. But having so many different models constructed and calibrated independently means that we can have confidence when the models agree.
Taking the whole range of climate models suggests a doubling of carbon dioxide could warm the planet by 2˚C to 4.5˚C, with an average of 3.1˚C. All the models show a significant amount of warming when extra carbon dioxide is added to the atmosphere. The scale of the predicted warming has remained very similar over the last 30 years despite the huge increase in the complexity of the models, showing it is a robust outcome of the science.

By combining all our scientific knowledge of natural (solar, volcanic, aerosols and ozone) and human-made (greenhouse gases and land-use changes) factors warming and cooling the climate shows that 100% of the warming observed over the last 150 years is due to humans.

Natural and Human influences on global temperatures since 1850. Carbon BriefCC BY

There is no scientific support for the continual denial of climate change. The Intergovernmental Panel on Climate Change (IPCC), set up by the United Nations to openly and transparently summarise the science, provides six clear lines of evidence for climate change. As extreme weather becomes more and more common, people are realising that they do not need scientists to tell them the climate is changing – they are seeing and experiencing it first hand.

This article is part of The Covering Climate Now series
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2050 is too late – we must drastically cut emissions much sooner

September 15, 2019

One of the last things that Theresa May did before she left office as the UK prime minister in July 2019 was to commit the country to a net zero carbon target in 2050. Weaning the entire economy off carbon-based fuels on this sort of timescale sounds ambitious, but several advanced economies have set targets considerably sooner than this.

Sweden and New Zealand are aiming for 2045, Finland for 2035 and Norway for 2030 – the most ambitious of any government. Extinction Rebellion has called for the UK to eliminate all carbon emissions by 2025. Our recent working paper explores the justification for these various targets.

The starting point is the global carbon budget calculated by the Intergovernmental Panel on Climate Change (IPCC). This is the total amount of carbon that can be emitted into the atmosphere from now until the end of this century. The most recent estimate of a global budget that would offer a 66% chance of limiting climate warming to within 1.5C above the pre-industrial average is 420 billion tonnes of carbon dioxide.

Working from here to a carbon budget for each country is both a technical and an ethical question. Using the UK as a detailed example, a simple proportional allocation would give the UK a budget of approximately 2.9 billion tonnes. But given the UK’s historical responsibility for carbon in the atmosphere and the undeniable need for development in the poorest countries in the world, there is a very strong argument that the UK should adopt a fair carbon budget somewhat lower than this. So, for example, if the poorer countries in the world were to have an allowable carbon budget just one-third higher than the richer countries, this would lead to a fair carbon budget for the UK of around 2.5 billion tonnes.

The question of how long this budget might last has no simple answer, because it depends how fast carbon emissions are cut over time. Remaining within any given budget depends inherently on the emissions pathway the country follows. If we cut emissions faster, we can afford a later target. If we cut too slowly, the budget will be exhausted, and we would be faced with the task of installing uncertain and costly negative emissions technologies to take carbon out of the atmosphere for the rest of the century.

The UK’s carbon footprint in 2018 was about 590m tonnes, measured on a “consumption basis”, which includes the carbon in imports but excludes that of exports. This footprint has been falling slowly (at around 1.5% a year) since 2010. But if it continued to fall this slowly, the carbon budget would be exhausted by 2023, in just four years’ time (Scenario a).

Even if we assume a straight-line reduction to zero emissions in 2050 (Scenario b), we would still generate a carbon overdraft approximately three times our allowable budget. In fact, the latest date by which we could draw a straight line from our current level of emissions to zero and still remain within the budget would be 2025 (Scenario c).

Four UK emissions pathways. (a) is based on our current rate of reduction, and (b) shows that linearly reducing emissions to net zero by 2050 means we’ll exhaust our carbon budget in four years. (c) shows that 2025 is the latest date we could linearly reduce our emissions to net zero, and (d) shows that for a 2050 target to stay within our budget, we’d need a 24% annual reduction in emissions. Tim Jackson/CUSP, Author provided

A target later than 2025 is possible only if the UK reduces emissions faster than the straight line pathway in the early years. In order to extend the target date for zero carbon to 2050, emission cuts would need to be in the region of 24% every year for the next three decades (Scenario d).

What is notable about this pathway is that, within little more than a decade, carbon emissions must already have fallen to a very low level. With a 24% annual rate of reduction, UK emissions in 2030 would only be 22m tonnes – less than 5% of the current level of emissions. Only a small programme of negative emissions technologies would be needed to achieve net zero at this point.

Clearly the challenge is still colossal. A 24% reduction in emissions amounts to a cut of 140 million tonnes in the very first year alone. The UK has never achieved anything close to this since its carbon footprint was first measured in 1990. In 2009, when the economy was in recession, the carbon footprint fell by 80m tonnes, while its best post-crisis reduction saw a fall of only 38m tonnes in 2016.

It is dangerously misleading for advanced nations to set target dates as far out as 2050. Doing so ignores the importance of staying within a fair carbon budget and gives a false impression that action can be delayed. In reality, the only way to ensure that any developed country remains within its fair budget is to aim for an early net zero target. For the UK, that means bringing forward the government’s target by at least two decades.

This might all seem daunting, but every year that progress is delayed, the challenge only gets bigger. Remaining within a fair carbon budget for the rest of this century requires deep and early decarbonisation. Anything else will risk a climate catastrophe.

“A complete transition to renewable energy sources saves around 65% of all current greenhouse gas emissions.” — Hans-Josef Fell

What is the most interesting fact from your research, something that you wish everybody knew?

HJF: Our research dispels the two most widespread falsehoods associated with renewables: high costs and supply uncertainty. Our newest study shows that a technology-rich energy system based on 100% renewables can supply secure energy at all times of the year in every region of the planet, at a cheaper cost as compared to today’s system.

CB: And this cost decline is possible without relying on high-risk technologies such as nuclear power and fossil carbon capture and sequestration (CCS).

And what lessons are to be drawn, which actions should be taken right now by governments all over the world, to avoid catastrophic climate change?

HJ: A complete transition to renewable energy sources saves around 65% of all current greenhouse gas emissions. 100% renewable energy pathways should, therefore, be at the center of any serious climate protection strategy. But for renewables to be able to thrive, we need to create favorable regulatory environments. Policy measures such as fixed feed-in-tariffs, tax exemptions and upscaled public funding will play a key role in increasing investments in renewable technologies and make them even more competitive. At the same time, we need to divest fossil-fuel assets, reallocate capital, and internalize the negative externalities of carbon-based and nuclear energy sources.

CB: Decision-makers need to become aware of the fact that investments into clean technologies will by far outweigh the direct and indirect costs of continuing with the current system. We calculated that a global 100% renewable power system will create 15 million additional jobs. The transition is absolutely necessary to save our planet and protect our economic welfare.

“Our planet will survive, no matter what happens. The question remains how many animal and plant species will survive the mass extinction caused by humankind.” — Prof. Dr. Christian Breyer

Would you say these ideas are getting picked up? Is the general mindset towards environmental protection changing?

CB: It’s no longer five minutes to midnight when it comes to climate change, it’s rather five seconds to midnight. Especially young people are more than just worried but leaders in politics and economy are failing on a global scale, despite the Paris Agreement. But there are a few individual frontrunners, both in politics and in the business sector, that have implemented serious climate protection strategies such as 100% renewable energy pathways. We see more rays of hope with the global Fridays for Future movement and the wave of solidarity for the young generation taking the streets around the world. This is exactly why we dedicated our most recent study to Greta Thunberg and the entire movement. They give us hope for change. However, hope is not enough, we need substantial actions, now.

HJF: The knowledge of the techno-economic advantages of renewables is gaining ground around the world. At the same time, the fossil-nuclear economic apparatus organizes all forces in order to protect its businesses. All the more important is research which debunks widespread myths surrounding the costs and energy security of renewables. The more our message prevails, the more optimistic we can be for the climate protection of the world.

What are your hopes for the future of our planet?

CB: Our planet will survive, no matter what happens. The question remains how many animal and plant species will survive the mass extinction caused by humankind. Even our civilization and humans as a species may be at risk. It’s not always easy to stay positive.

HJF: But our work shows that we can be if we only take action. We can succeed in averting the catastrophic earth-heating. A rapid transition to 100% renewables is at the core of such a strategy. Costa Rica, California and other states already went ahead with the implementation of relevant laws and set great examples. Yet, many obstacles, especially upheld by the old, fossilized business world, remain and need to be overcome.

What is the most pressing endeavor for you today? Do you have new projects in the pipeline?

HJF: The protection of the world’s climate is our most pressing concern.

CB: … and in order to do real justice to this aspiration, our desired project would be the realization of a 1.0° C scenario until 2100. This scenario would stand for real sustainability. The truth is that even with 1.5°C global warming, glaciers and the ice on Greenland will vanish, thus many coastal cities around the world are most likely doomed already, for instance New York, Shanghai, Amsterdam, Mumbai, Jakarta, Stockholm or Tokyo. The only problem: nobody wants to finance such an “ambitious” scenario. Despite our conviction that it will be technically feasible, economically viable and most importantly, necessary for civilization to survive.

HJF: As a next step, we are now using the big dataset and calculation models we developed, as well as our political experience to provide plans for individual countries to switch to 100% renewable energy. We need political leaders on all levels to assume responsibility and take climate action.

Read the full study here.

A globally recognized expert on energy policy, Hans-Josef Fell has helped to pioneer the ecological movement in Germany since the 1970s. As a Member of the German Bundestag for the Green Party (1998–2013), he co-authored Germany’s Renewable Energy Sources Act, the most instrumental tool for the deployment of renewables, replicated over 100 times worldwide. Since 2014, he has been President of the Energy Watch Group, an international network which analyses global energy developments, commissions independent research on energy and provides advice for governments and parliaments around the world.

Christian Breyer is Professor for Solar Economy at LUT University, Finland. His major expertise is the integrated research of technological and economic characteristics of renewable energy systems specialising in energy system modelling for 100% renewable energy, on a local but also global scale. He worked previously for Reiner Lemoine Institut, Berlin, and Q-Cells (now: Hanwha Q Cells). He is a member of ETIP PV, IEA-PVPS, the scientific committee of the EU PVSEC and IRES, chairman for renewable energy at the Energy Watch Group and reviewer for the IPCC.