Lennart Bengtsson is a Swedish climate scientist who has just published a book (in Swedish) against climate catastrophism and urging governments and others to look at the beneficial effects of global warming as well as the problems. This is part of an interview with Dr. Bengtsson by Die Welt (The World), a German newspaper, on June 15, 2022.
WELT: Mr. Bengtsson, are we living in a climate crisis?
Lennart Bengtsson: I don’t think the current warming should be called a crisis. Global food production, for example, is increasing. And despite a rapidly growing population and continuing warming, far fewer people die as a result of extreme weather than in the past. The current acute problems of conflicts and wars are caused by the difficulty of finding, quickly enough, reliable substitutes for fossil fuels. Nevertheless, we do need long-term and systematic action to reduce global greenhouse gases to curb warming.
WELT: Should the Paris Climate Agreement serve as the guideline for restricting the CO emissions?
Bengtsson: In my opinion, the Paris goals are too ambitious for the European Union in particular and should be adapted to what is technically feasible in order to avoid acute economic problems for the industry and the public. Every effort should be made to reduce CO2 emissions everywhere, also in emerging countries. If greenhouse gas emissions are not implemented worldwide, further warming won’t be contained.
WELT: What two problems do you think are the biggest caused by global warming?
Bengtsson: Sea-level rise is problematic in some areas, but that can be countered by the construction of coastal defenses, as is the case, for example, in the Netherlands. Changes in precipitation are all the more serious, the larger the areas are that are affected. Climate models simulate this, and there are good theoretical models that suggest that areas with heavy rainfall will become rainier and currently dry areas could have even more problems with drought. So far, however, there is no clear empirical evidence that such changes have taken place. They are also very difficult to separate from random natural events.
More emphasis needed on adapting to climate change
WELT: Is there too much talk about greenhouse gas reduction and not enough about adaptation to climate change?
Bengtsson: Yes, indeed. The number of people dying from extreme weather events has decreased significantly due to more accurate forecasting and improved warning systems. I’m afraid the news media are often not in the picture on this subject, they often present too much of a simple picture. In fact, far more people die from the cold than from the heat. The coming winter could be very serious in Europe. Already in the UK there are fears that many elderly people in apartments and houses could die next winter if they they cannot afford to heat their homes.
WELT: In your book you criticize the popular attribution of weather events as a result of global warming. Why?
Bengtsson: Most extreme weather events are not caused by high temperatures but are caused by temperature differences. This is why storms are more intense during the winter season. In fact, it is to be expected that certain weather extremes such as extra-tropical storms could become even weaker in a warmer climate. Local damage caused by extreme precipitation is often reinforced by infrastructural changes such as roads and parking lots that prevent water to penetrate into the groundwater quickly enough. The effect of global warming on weather disasters is usually not so easy to identify.
Climate change not major source of social problems
WELT: Can climate science make robust statements about social developments caused by climate change?
Bengtsson: I don’t think so. Social developments that we currently observe so clearly usually have nothing to do with weather and climate but with social events such as political incompetence, conflicts and wars. Because of of the enormous population growth in the 20th century (and because of that more infrastructure can be devastated), human settlements are now more exposed and more vulnerable to extreme weather. A climate effect is not so easy to identify.
WELT: In order to detect a man-made climate signal, natural variability must be well understood. You have said that natural climate variability is still not sufficiently understood. Where are the problems?
Bengtsson: The best current climate models reproduce typical weather systems pretty well, including typical variability, such as typical differences year by year. We have good reason to conclude that the colder periods in the 1960s and 1970s were caused by random events. We are less confident about the significant warming from 1910 to 1940. And there is no credible explanation yet yet for the causes of the Little Ice Age from 1350 to 1850.
Climate fluctuations on time scales of one hundred to several hundred years are not understood and also not well reproduced by current climate models. On the other hand there is compelling empirical evidence for ice ages consistent with the astronomical cycles. Global warming over the last 40 to 50 years, however, is clearly related to the greenhouse effect, albeit regional differences in warming require better scientific understanding.
We need more discussion of warming benefits
WELT: You complain that there is not enough talk about the benefits of warming. Which ones in particular?
Bengtsson: I find it difficult to accept that a warmer climate is higher latitudes should be negative. An ice-free Arctic Ocean will encourage and enable more fishing, simplify shipping and transport and create better living conditions, better opportunities for farming and more productive forestry in places like Canada, Scandinavia and Russia.
WELT: “Nothing is more important than unbiased curiosity research,” you write in your book. Is climate research no longer impartial and open?
Bengtsson: Much less today than 20 to 40 years ago. I’m afraid the smartest scientists today are looking for other areas where science is more open.
WELT: In your book you call for a more open debate and criticise “groupthink, which prevents rational analysis”. What do you mean?
Bengtsson: I think the general public debate tends to regard all climate change as something negative, without pointing out that some climate changes are positive or even natural processes that have always existed. The warmer climate in Europe today is more favorable for society than the typical climate of the 19th century.
In fact, the warming observed in the 1930s was seen by almost everyone as something generally positive. I fear that the strong politicization of the climate debate has negative consequences for basic research, as some scientists are naturally skeptical and critical. That’s why some scientists hesitate to scrutinize issues that some universities and funding agencies could regard as being too critical of the Intergovernmental Panel on Climate Change (IPCC).
WELT: The IPCC was supposed to create a scientific consensus. Has that been successful?
Bengtsson: It is obvious that there is consensus in many areas, such as at basic mechanisms of the general circulation of the atmosphere and the oceans and also that more greenhouse gases in the atmosphere lead to a warmer climate. But there are disagreements about how fast the warming is taking place and how damaging the warming could be. There isn’t a real consensus on whether or not extreme weather has gotten worse, and certainly
no consensus on what caused the Little Ice Age.
WELT: The Earth’s temperature has risen by about one degree Celsius and will continue to do so, probably going up a degree or two this century, you write in your book. What do you say to young people or your compatriot Greta Thunberg, who is in panic over this prospect?
Knowledge is best medicine against climate fear
Bengtsson: My recommendation to the younger generations is that they engage intensively with the topic and learn more about the climate system. Knowledge is my opinion the best medication against climate fear.
WELT: What makes you optimistic that climate change can be slowed down?
Bengtsson: Significant scientific advances, more reliable weather forecasts and better understanding of the climate system. Secondly: Observations show that global warming is happening more slowly than in most computer simulations. Thirdly: Emissions of greenhouse gases among the OECD has declined significantly over the past 10 to 15 years. There’s reason to assume that this trend will eventually also happen in emerging markets within a few decades. Fourthly, I have strong confidence in the scientific and technical ingenuity of people and believe that this can thrive if we can maintain the current level of intensive research and the good international cooperation. The most advanced countries can fund basic research to develop new methods of energy production with minimal negative impact on the environment. In 100 years, I believe, climate change due to greenhouse gases will no longer be an issue.