It is certain that global average annual temperatures have increased, and the rate of increase has accelerated, over the past 135 years. It is also certain that warming will continue, and perhaps continue to accelerate, over the coming decades.
Forecasts vary but – even with our best effort at mitigation – global average annual temperature increases totaling between 3 and 9 degrees Fahrenheit over the next 85 years seem likely. This will be accompanied by sea level rise, estimated to be between 8 and 20 inches. And these forecasts are for global average increases; some places will see increases in daily high temperatures that are much greater than 9 degrees Fahrenheit, and for some coastal topography a sea level rise of a couple of inches is a disaster.
We know, from ice-core research and paleo-biology, that over the past million years the Earth has warmed and cooled substantially in short periods of geological time – several hundreds of years. But humans have not been around for many of those shifts and we have no meaningful record of human adaptation to those changes. Further, there are big differences between a few thousand hunter gatherers migrating south or north and the challenges facing 7.6 billion people, most of them in urban concentrations, spread throughout the globe.
The obvious conclusion is that we don’t really know what is going to happen to human populations, or life as we know it, as the planet warms. Pick almost any first order impact you like – storm or drought intensity, sea level rise, changing ocean currents and temperatures, extreme heat events, impacts of warming on human disease vectors – and you find deep uncertainty.
It is even worse when first order global warming impacts tumble through a profoundly linked economy. What happens to food security when flooding regularly but unpredictably cuts off certain parts of a city? What happens to a tourist industry when a destination is no longer desirable because it is too hot or wet or dry? How much do we have to starve other public services to raise an airport runway or harden a sea port against sea level rise?
In the context of this uncertainty, magnified by the need to act despite a lack of meaningful precedents, there are four things we need to do now to address for global warming:
1. Increase focus and resources to improve the quality and availability of usable information. Human adaptation to global warming is the sum of distributed decisions. Individuals, companies, and governments need much better localized information than currently exists about the changes and risks associated with global warming.
2. Increase investment in adaptation-focused research, development and demonstration (RD&D). A substantial increase in breadth and depth of adaptation problem-oriented RD&D is needed. Solutions are needed in topics ranging from human health and food security to infrastructure and natural resource management. And, of course, disaster preparedness, disaster response and population relocations.
3. Plan for the public and private economic costs of adaptation. Individuals, companies and governments have four approaches to preparing for future and unanticipated expenses: a) reduce other expenditures; b) reserves; c) insurance; and d) borrowing. The process of developing – and publishing for review – funding strategies for different levels of adaptation costs would be a good first step for both governments and companies.
4. Strengthen policies and plans related to adaptation. There is a real risk that the nation will look back from 2040 and realize that our responses to the challenges of adaptation were too little, too late. We need to increase the level of attention and resources dedicated to evaluating national, state, and local levels of preparedness. Policies and plans for risk management, crisis avoidance, and for protecting vulnerable populations should be the focus of that effort.
Famously, Thomas Malthus predicted (in 1798) that population growth would outstrip the planet’s ability to feed the population. Malthus is far enough in the past, was wrong enough, and yet was credible enough when he first made his arguments to have his name be incorporated in the lexicon of failed predictions: a Malthusian fallacy is a forecast of doom based on current trends that does not take other changes into account. History shows us that the "other changes" not accounted for in Malthus' projection were human ingenuity, the ability to adapt.
In Malthusian terms, adaptation to global warming – the sum of distributed decisions and actions by citizens, governments, and companies – is a new and significant challenge to human ingenuity. We need to be ingenious enough to develop more useful forecasts, invest in problem-oriented research for adaptation, plan for the costs and economic consequences of global warming, and strengthen policies that mitigate risk, help avoid crises, and protect vulnerable populations. Clearly doable, but best we get started now.