Climate Change is Not Debatable

Climate change is not debatable and yet the debates continue. The debates are a distraction from making any progress on addressing the problem.

There are in fact three very different climate-change debates going on today: a scientific debate, a world leadership debate, and a public debate.

Most scientists agree that climate change is a real and existential problem (Figure 1). The scientific debate is about how much of a threat climate change is to human life and civilization.

World leadership generally agrees with scientists but believes that there is a technology solution for carbon emissions. The leadership debate is about which technology will reverse or slow CO₂ emissions.

The public is more divided about the seriousness of climate change partly because of populist influencers who peddle the narrative that climate change is a hoax. The public generally accepts that climate change is real but does not believe it is the most important problem facing the world. The public debate is whether doing something about climate change is worth the cost.

The Scientific Paradigm

These categories of debates are, of course, broad generalizations but they help to explain why there has been little progress addressing the problem of a warming planet.

Let me be very clear about one thing: the ruling scientific paradigm today is that climate change is caused by CO₂ emissions linked largely to burning fossil fuels.

That is not debatable.

The tiresome populist argument that climate change is a hoax, however, goes on because many people are psychologically unwilling to accept that this is the best explanation for a warming earth.

Global warming is an empirical fact. That is not debatable.

The mean surface temperature of the earth has increased to nearly  1° Celsius more than the 100-year average (Figure 2). It is expected to approach the dangerous level of  1.5° Celsius more than that 100 year average in the next few years.

Out of more than 88,000 peer-reviewed papers on climate change since 2012, 97% supported the ruling paradigm. Deniers point to a handful of scientists who disagree and say that this “so-called consensus” is wrong; or they cite a few incorrect forecasts about climate change and say that this proves that climate-change is a hoax.

That is wrong and dishonest. The overwhelming agreement among scientists is not debatable. It is what defines the current scientific paradigm.

A paradigm is a theory that seems to explain observed facts better than competing theories. It is a set of universally recognized interpretations of data, methodological processes and concepts by the present scientific community.

Thomas Kuhn was a renowned physicist whose 1962 book The Structure of Scientific Revolutions defined the paradigm in modern scientific work.

“Paradigms gain their status because they are more successful than their competitors in solving a few problems that the group of practitioners has come to recognize as acute.
–Thomas Kuhn

That doesn’t mean that the paradigm is correct for all time. It merely means that it is the explanation that best integrates all available data.

Kuhn stated that a  paradigm is established when a world-view or theory is “embraced by almost all practitioners” and becomes part of the practice of  “normal science.” The ruling paradigm is accepted as a first principle in new published research. It no longer needs to be proven each time it is stated because it is broadly accepted.

This is how science has worked for centuries. There is nothing special about the climate-change paradigm that didn’t apply to plate tectonics, germ theory, quantum mechanics or any new scientific paradigm.

When debate within the competitive and contentious scientific community devolves from a roar to a whimper, a new paradigm is established.

The Populist Argument is Wrong

The main populist objections to the ruling scientific paradigm include:

• that climate is always changing and is part of a natural process;
• that there were higher CO₂ and temperature levels during the time of dinosaurs and life went on just fine;
• that some predictions about the timing of climate change were wrong;
• and that CO₂ and warming don’t correlate perfectly.

These shop-worn objections have been around for decades and have been debunked or shown to be without material substance in the larger systemic context.

For example, dinosaurs had a vastly different tolerance to temperature and CO₂ than humans. There may have been 20 million dinosaurs on earth at their peak during the Cretaceous period about 66 million years ago. They lived relatively simple lives in small herds or alone.

There are now 8 billion humans living in a complexly connected civilization that relies on global supply chains to move goods and services all around the planet. Comparing the present and near-future for humans to conditions for now-extinct creatures in the deep geological past is simply absurd.

Another example: climate-change deniers can easily find  a few credentialed climate experts who disagree with the ruling paradigm—just like every attorney can find expert witnesses whose testimony supports his client’s plea.

Similarly, it is easy to find a climate expert who made a prediction that didn’t come true. Human history is littered with bad predictions and dissenting experts. Failed predictions and even bad scholarship are sadly found in many areas of society, not only in climate science. But the exceptions do not prove the rule.

Paradigms are explanations. There is no requirement that we like them. Einstein never liked quantum theory but he could not support his belief except to say that, “I, at any rate, am convinced that [God] does not throw dice.”

The climate-change debate, however, is not a competition. There is more than adequate information to suggest that climate change presents some probable risk to human prosperity and to other species. Like it or not, the scientific debate about climate change ended years ago.

Technology Won’t Save Us

Figure 3 is the single most important chart for understanding that the climate debate is about more than just carbon emissions.

It shows the normalized and scaled correlation between economic growth (GDP), the human material footprint on earth’s ecosystems, carbon emission (CO₂) levels, and human population.

Climate change is not just about the carbon that human activities produce but how effectively earth’s forests, oceans and atmosphere are able to process those emissions. That is 100% correlated with economic growth. Economic growth is 100% correlated with energy consumption. All are directly related to population growth.

The conclusion is clear: carbon emissions and overshoot of planetary boundaries are unlikely to decrease as long as world GDP and population continue to increase. All four factors in Figure 3 are related. Nothing can really be done about reducing carbon emissions without also reducing population, humanity’s ecological footprint, and GDP.

Figure 3 is not debatable. You don’t have to like it or agree. It is historical fact.

The path that world leadership is following is based on technology optimism.

When the International Energy Agency issued its Net Zero by 2050 report in May 2021, U.S. climate envoy John Kerry made these comments.

“I am told by scientists that 50% of the reductions we have to make to get to net zero are going to come from technologies that we don’t yet have. That’s just a reality…You don’t have to give up a quality of life to achieve some of the things that we know we have to achieve. That’s the brilliance of some of the things that we know how to do.”

Figure 3 indicates that Mr. Kerry is totally wrong.

He is wrong because he and world leadership are only focused on carbon emissions. But emissions are not the problem. They are the result of the problem. CO₂ emissions are simply the waste produced by 8 billion people consuming energy every day. The problem cannot be solved by addressing the symptom without also addressing the causes.

World leaders and many climate activists have carbon tunnel vision (Figure 4). They do not see that carbon emissions are a systems problem.

In fact, climate change itself is a systems problem. It is a symptom of too many humans, using too many resources, producing too much waste and overshooting earth’s capacity to recover. Humans have exceeded the carrying capacity of the planet.

The original meaning of carrying capacity was the amount of cargo a ship could carry without a risk of sinking. Our ship is Planet Earth and we have overloaded it with people consuming its resources and polluting its land, water and air.

Efforts to reduce carbon emissions have failed and will probably continue to fail. The dashed green line in Figure 5 is the International Energy Agency’s (IEA) 1.5° C pathway to net-zero carbon emissions by 2050. It is what must happen to avoid serious climate-change risks to humans and the planet.

The most likely projection (black line) suggests that the world is seriously off-track in meeting that net zero pathway.  It seems that even the more dangerous 2.0° C pathway may also be exceeded.

How is it possible that things look so bad in spite of all the laws, regulations, technology and money devoted to the problem?

It is because all models and projections (including the IPCC scenarios) assume continued population and economic growth.

IEA’s net zero scenario in Figure 4  includes an approximate doubling of world economic growth by 2050 averaging 3.1% from 2020 to 2050. The EIA case assumes 1.7% economic growth for OECD countries and 2.6% for non-OECD countries.

Without a change in population and economic growth, temperatures will enter a danger zone for life on the planet in the next few years.

That is not an alarmist statement. It is common sense. It is the inevitable result of historical data trends.  If the trends don’t change, the outcome is unlikely to change.

There’s really nothing to debate.