You can lead people to data, but you can’t make them think

A new analysis issued by the National Academies of Science, Engineering, and Medicine has found that the evidence linking rising greenhouse gas emissions to negative human health outcomes is “beyond scientific dispute”.

This report was carried out rapidly in response to threats by the US administration to reverse the 2009 declaration, known as the endangerment finding, which determined that carbon dioxide, methane and other greenhouse gases threaten human health and can be regulated under the Clean Air Act.

The US has already withdrawn from the Paris Agreement, an international treaty on climate change adopted in 2015 to limit global warming to below 2C, preferably 1.5C compared to pre-industrial levels.

The reality of climate change caused by humans has, once again, been confirmed, and in fact amplified. Yet there are many who do not agree. US President Donald Trump and his minions have been extremely critical of those of us who talk about the reality of climate change, as have many other so-called conservatives. Climate change is not a matter of opinion; it is scientific fact, based on observations, scientific theory and understanding.

The composition of the atmosphere has changed and it is warming up; the result of humans increasing carbon dioxide by over 50 percent since about 1900, for example. Moreover, the global temperatures continue to climb and are now 1.5C above preindustrial values. Theory, laboratory experiments and observations show that carbon dioxide is a greenhouse gas and causes heating by trapping radiation that would otherwise escape to space.

The flows of energy through the climate system are continuously monitored by satellites. Climate models based on theory can replicate the climate observations quite well and simulate the observed changes and make predictions of the future. The results are alarming.

I’m a climate scientist, not a psychologist, so I can only speculate on why some people would think of climate change as some kind of fiction created by scientists, manipulating our politicians.

Some folks may fear the future and prefer to reject the basic facts out of hand. Some may reject facts due to cognitive biases, or because of perceived threats to personal or group identity when facts challenge beliefs, perhaps based on religion. There may be mistrust of the information source, and misinformation (on social media especially), which makes it difficult to distinguish trustworthy information from falsehoods. Individuals with strong ideological identities may rationalise and evaluate information to align with their desired, rather than objective, conclusions.

Facts that contradict deeply held beliefs can trigger defensive reactions or a ‘backfire effect’, where people become even more entrenched in their original views. Some may have vested interests which inform their decision not to accept valid scientific information.

Hate mail, misinformation and disinformation are running rampant, particularly in the US. Hate mail is generally protected by the US Constitution’s First Amendment, but that protection does not extend to deliberately misleading content – what we now call disinformation.

Trump and his cabinet have promoted deliberate disinformation about climate change and ways to move forward, including the potential of renewable energy, especially solar, wind, and hydro. Already developments have made renewable energy more cost effective than the use of fossil fuels.

A report published in June by the International Panel of the Information Environment, Fact, Fakes, and Climate Science, found that “powerful actors – including corporations, governments, and political parties – intentionally spread inaccurate or misleading narratives about anthropogenic climate change. These narratives circulate across digital, broadcast, and interpersonal communication channels. The result is a decline in public trust, diminished policy coordination, and a feedback loop between scientific denialism and political inaction.”

Climate change is real, caused by human activities, particularly by increasing greenhouse gases of carbon dioxide, methane and nitrous oxide. As these are long lived and globally distributed they produce global warming. Other facts are not as apparent. The increases of many extremes that occur in various weather events is well documented and associated with climate change, but the relationships are difficult to unpack; they depend on the weather, and how climate change affects storms and weather patterns.

Not only have temperatures risen by 1.5C, mainly since the 1970s, but increases in heat waves have also caused substantial loss of life and damages. As temperatures rise, the water-holding capacity of the atmosphere increases by 7 percent per degree celsius, and this is happening over the oceans.

But land temperatures are rising faster than ocean temperatures, so as moisture moves onto land as part of the hydrological cycle (ocean evaporation, wind transport of moisture to land, rain on land, run-off and flow of water in rivers back to the ocean), the relative humidity on land drops. We’ve observed this since 1990.

Because the onset of rainfall depends on relative humidity, this means rain events are fewer. But when they are triggered by weather systems, they become larger, more intense and more likely to cause flooding. The result is longer dry spells, increased droughts, heatwaves and wildfires, and greater risk of floods – all of which cause huge disruption and costs as well as loss of life. The scientific understanding of this process in the context of climate change is evolving.

To say that climate change is not real constitutes harmful disinformation. Scientific facts, understanding, and observations provide ever-increasing support, as detailed in the National Academies report. Widespread flouting of pledges to the Paris Agreement, including by New Zealand, means that climate change is running amok, with few signs that progress is being made in containing it.

Prospects for the future are becoming grim. Ten years after the Paris Agreement, a shared promise to a better future, countries are baulking on their commitment to addressing the world’s greatest challenges. Instead many are affirming their commitment to the use of oil and gas.

In the absence of progress towards sufficient decarbonisation to rein in human activities that cause climate change, which is very much a global problem, the option for small countries and individuals is to plan for the consequences.

This is so-called adaptation and building resilience: paying special attention to rising sea levels and coastal inundation, building better drainage systems to deal with torrential rains and flooding, managing water to deal with droughts and wildfire risk, and protection from heat waves. Increasing extremes in weather are already occurring and prospects are for more of the same.

Scientists like to present the facts, and the data to back them up. Our data paint a dismal future, unless we work collectively to avoid it. We have the capacity to do so. It is confounding to scientists that some folk would prefer to deny what we know about looming threats, and carry on as if it’s not going to happen. As founder and executive director of the Presidential Climate Cation Project Bill Becker has said: “You can lead people to data, but you can’t make them think.”