What will our descendants think?

The American baseball player and coach Yogi Berra once said: “It’s tough to make predictions, especially about the future.” He was right, and I say this as a climate scientist who deals with climate change and its impacts – making good predictions is difficult.

In 2007, I wrote an article entitled, “The Way We Will Be 50 Years From Today”. I noted then that “a credible prediction of something bad will likely prove wrong simply because we, as humans, have the power to alter what happens in many cases”.

In my own field of climate science, this is certainly the case. Humans are changing the climate owing to changes in the composition of the atmosphere, mainly increases in carbon dioxide, from burning fossil fuels and other human activities. Current trends, if continued, suggest climate change could lead to a very different planet, sooner or later, and the question is do we, as the peoples of the planet, have the wherewithal and political will to make sufficient changes to make a difference and alter the outcome?

I have been involved in climate research since the 1980s and heavily engaged in the Intergovernmental Panel on Climate Change scientific assessments of climate change.

In these assessments, changes in the concentrations of gases and aerosols were estimated using idealised “what-if” emissions scenarios – informed estimates of what might happen in the future under various sets of assumptions related to population, lifestyle, standards of living, carbon intensity, etc. Changes in future climate, based on these scenarios, were estimated. The output of such models is referred to as a projection – not a prediction or forecast.

Unlike a weather prediction, the models do not start with the current state of the climate system, as derived from observations. Examining only the change in projected climate effectively removes biases in simulating the current climate. This technique works quite well. Only recently has the climate panel made predictions on a 30-year time frame.

As I wrote in 2015: “It is very difficult to predict the future over 50 to 100 years especially if one considers just climate change. The population continues to grow, many activities are unsustainable, and there are many unknowns related to major wars and conflicts and pandemics.” I then argued, and would still argue, that the burgeoning population and its demands on resources was a bigger problem than climate change.

We humans are fouling our own nest, in part by changing atmospheric composition. It wasn’t so much of a problem when there were just a few billion of us, but now there are more than 8b living unsustainably. It seems likely we will continue to boom and then bust, one way or another.

With regard to climate change, I think the biggest impacts on society will be through water because of increasing demand and the effects of climate change: more intense, extensive and longer-lasting droughts, and more intense rains and flooding risks, and tropical storms. Coastal regions increasingly get pounded by storms as sea levels continue to rise and many major coastal cities may no longer be viable, much more so in so-called developing countries. Increasing risk of heatwaves and wildfires, shortages of water and food, and outbreaks of bugs and disease, seem likely to create widespread environmental refugees, and it all leads to increased pressures that make conflicts more and more likely. What happens when regional becomes intercontinental?

The way the world operates is unsustainable, as various countries routinely consume more resources than available globally in the long term. Many wonderful developments and drugs have emerged that have saved lives from disease and infection, for instance by the Gates Foundation, but there have been no comparable efforts to deal with the consequences of increasing populations.

It is hard to keep count of the regional conflicts over the unequal distribution of resources, territorial disputes, economic disparities, ethnic tensions and climate issues, aided by weak governance, authoritarian regimes, and terrorism.

Strong shifts to the right in many Western countries have led to growing rebellions of local populations and increasing migration. This is perhaps a very cynical way of understanding how the world deals with population pressures: by not dealing with it.

Meanwhile, climate change continues unabated. Rosy prospects after the Paris Agreement in 2015 have had major setbacks, and “net zero” is now a pipe dream. There is widespread belief among scientists that nowhere near enough is being done to curb climate change and that it could result in an existential threat to civilisation.

By the time the global temperatures have reached 2C above pre-industrial temperatures, scheduled now for the 2050s, not only will there be continual extreme weather events, but the average climate will have changed so that crops now grown can no longer survive; water shortages will become widespread; and food will be in short supply. The result will be widespread environmental refugees, exacerbating tensions and regional conflicts that could explode to encompass many countries. Plus further complications from the odd pandemic.

Decarbonisation has made some progress, and renewable energy is often now viable. It is cheaper than other forms of energy and growing in many developing countries, but not encouraged in some quarters or by the fossil fuel industry. Instead the prospects are for global warming of over 3C this century, along with increasing weather extremes and wildfires, rising sea levels and destruction.

The role of scientists is to lay out the facts and the prospects and consequences, but we don’t get to decide what to do with this information. That involves everyone.

Value systems, equity among nations, equity across generations, vested interests, the precautionary principle, ideology, and many other factors come into play to decide whether to do nothing and suffer the consequences or try to do something about it.

A certain amount of warming is guaranteed, but there is the capacity to change the outcome, if there is a will to do so. A carbon tax and other mechanisms that put limits on emissions provide ways to give incentives and encourage innovation if the tax income is applied to solutions and to offset damages. With incentives and new funding for research, technical innovation could revolutionise the way we do things. But equity among nations will be difficult to achieve.

The outstanding issue is our generation’s stewardship of the planet, and what amounts to inter-generational equity. History will likely judge our generation as one of undue affluence through a lifestyle that exploits the planet’s non-renewable resources and jeopardises the sustainability of the whole planet. A strong leadership role in seeking solutions and bringing peoples of the world together to achieve sustainable pathways is much needed. Otherwise I predict our descendants will look back at the wonderful resource of petroleum in the 20th century and lament that all we did with it was burn it.