Global average annual temperatures have increased, and the rate of increase has accelerated, since the late nineteenth century. The extent of global warming in coming decades depends on future emissions of greenhouse gases, and even perfect mitigation to reduce emissions can only slow the pace of future warming. We cannot stop global warming in its tracks. Therefore, we need to adapt. But what are we adapting to?
Global average annual temperature is estimated to increase between 4.5 and 9 degrees Fahrenheit by the end of the century. This will be accompanied by average sea level rise of between 8 and 20 inches. These forecasts are for global average increases. Many locations will see peak temperatures increase even more, and during storms an increase of inches in the sea level can translate into floods measured in feet, not inches.
The likelihood of first order effects—extreme heat, drought, flooding, more severe storms, increased food insecurity, and the poleward spread of tropical diseases—is well known. We cannot, however, accurately forecast the magnitude and geographic distribution of effects over the next 50 years, because of both uncertainty about the future emissions of greenhouse gases and the challenge of determining how large-scale climate changes will affect local-scale climate.
An even greater challenge will be to predict the second order effects as first order effects 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 funding for local public services will have to be redirected to raise an airport runway by six feet or harden a seaport against future storm surge?
In sum, we do not know what is going to happen to the built environment, landscapes, and ecosystems that we depend on as the planet rapidly warms. If this were not bad enough, there are credible climate scenarios in which the planet reaches a tipping point that results in runaway changes in climate and sea level.
This unprecedented uncertainty about the future raises another set of issues regarding adaptation. Is it enough to prepare airports, farms, social safety nets, and emergency services to deal with creeping sea level and temperature rise? Or should we also prepare for large discontinuities in climate and worst-case events?
In the context of this uncertainty, magnified by the need to act despite meaningful precedents, there are four things we need to do now to address global warming:
1. Improve the quality, accessibility, and usability of climate hazard and risk information. Human adaptation to global warming is the sum of distributed decisions. Individuals, companies, and governments need much better and more locally relevant information than is currently available. The forecasts that are available are incomplete, not fine-scale enough, too infrequently updated, and disconnected from critical decision-making.
For the past several decades climate scientists have been focused on understanding the relationships among human activity, greenhouse gases, and global climate change. Their findings make a strong case for curtailing or changing certain human activities. In recent years, some researchers have shifted to understanding and modeling likely regional climate effects. This is critical for adaptation, and it needs to continue.
Although there are many well-meaning efforts to offer predicted climate data in support of local climate adaptation, the data that climate science can provide are inadequate. The information is too coarse in resolution, too uncertain, and too far in the future for cities, companies, and communities to use in their planning. Often, climate science can assess the magnitude of change, but cannot compare adaptation options. Significant gaps exist between the way scientists think about climate adaptation and the information citizens, governments, and company leaders need to make decisions or plan for the future.
Individuals buying homes or renting apartments need access to accurate and easy-to-understand presentations of location-specific flood risks; engineers, architects, and planners creating new facilities, or updating existing infrastructures, need to be able to anticipate climate hazards and risks far in the future; emergency services leaders need reliable estimates of the number and distribution of flooding or extreme heat days in their service area over the coming few years; and investors and insurers need reliable short- and longer-term predictions of climate change effects at a regional or even site-specific scale.
Governments can and should lead to remedy this situation, but the work will need to be done in collaboration with the variety of companies that have capacity in geoscience analytics, sensors, and map-based information presentation, as well as with an emerging cadre of adaptation professionals.
2. Increase investment in adaptation-focused research, development, and demonstration (RD&D). A substantial increase in breadth and depth of adaptation-oriented RD&D is needed. Solutions are needed in diverse areas, including human health and food security, infrastructure, urban systems, and natural resource management. And, of course, disaster preparedness and disaster response. This investment necessarily includes increasing the human capital for adaptation-related RD&D.
If research is exploration, applied research is problem solving. Applied research on human adaptation to global warming is woefully underdeveloped. Uncertainty about the scope and scale of the problem explains some of the current shortfall in applied research. Additional impediments are that critical applied research for adaptation is spread across literally dozens of disciplines and subdisciplines of engineering, science, social sciences, and medicine, and that critical expertise can be found in academia, governments, and the private sector. Mobilizing a dispersed and varied community of problem solvers to address a future threat of uncertain character and magnitude is inherently hard.
Some governments and corporations are beginning to integrate climate change adaptation into their strategic planning, provide resources to encourage others to do the same, and even organize research funding around adaptation challenges. For example, two international groups, the Adaptation Fund and the Special Climate Change Fund, both established under the United Nations Framework Convention on Climate Change, have mandates to fund adaptation efforts. In the United States, there are landmark federal efforts focused on adaptation, including the National Oceanic and Atmospheric Administration’s Regional Integrated Sciences and Assessments program and the Department of Interior’s Climate Adaptation Science Centers. Nonetheless, the bulk of federal funding for climate change work is focused on technology to reduce emissions. Private companies in mining, agriculture, and beverages have had to adapt to water scarcity through conservation and reuse, and consumer goods companies change their product profiles to react to weather patterns. Publicly traded companies in all sectors are under increasing pressure to predict and disclose climate-change-related liabilities as part of their financial reporting. These shifts are laudable and provide important background for action, but they are far from adequate to the challenges.
The nation’s RD&D enterprise—both government-funded and industrial—is decentralized but robust and can be responsive to well-articulated problems. It helps, of course, if funding accompanies the problem articulation. There are relevant RD&D programs at many federal agencies and in some states (e.g., California), but the scale is small relative to obvious needs, and the number of professionals with the necessary skills is small. A national effort to collate and update information on private, federal, and state government expenditures on adaptation-related RD&D, as distinct from overall climate-related RD&D, would be a good first step for linking existing adaptation efforts and identifying gaps.
With regard to global collaboration to reduce the national burden of adaptation-focused RD&D investment, the United States needs to be both strategic and tactical. It should make a fair contribution to the shared global RD&D enterprise without losing sight of problems that are critical for domestic needs, taking advantage of the value of shared investigations and global experience when possible.
Global networks of exchange and collaboration exist in almost every field of science and engineering, and this is the case for all the fields relevant to climate change adaptation. These need to be strengthened. The US government, universities, and companies need to be aggressively active on adaptation, including taking leadership roles in adaptation networks, so the nation can contribute as well as benefit. In today’s interconnected world, RD&D is a global enterprise, and it is foolish to ignore what is going on worldwide.
3. Plan for the public and private economic costs of adaptation. Individuals, companies, and governments have four approaches to preparing for uncertain future expenses: plan to reduce other expenditures, develop and then tap reserves, buy insurance, and borrow. 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.
There are a couple of reasons why we are unprepared for the costs of adaptation to global warming. First, there is genuine uncertainty about the timing and severity of effects. We do not know what adaptation will cost or when the bill will come due. That is true for individuals, state and local governments, and companies, as well as for the United States as a whole. Second, despite the uncertainty about just how bad it will be and when it will occur, we know global warming is bad news; any reasonable estimate of the funds required to adapt successfully is a large and scary number.
The American Society of Civil Engineers (ASCE) estimates a $2 trillion shortfall between planned funding and funding needed to maintain the US infrastructure between 2017 and 2025. Taking a single infrastructure system that has obvious connections to climate adaptation, the ASCE has estimated the near-term cost of fixing the nation’s 30,000 miles of levees at $80 billon. As global warming challenges our infrastructure those costs will certainly increase, and the United States is not prepared even to estimate those costs. The $1.5 trillion infrastructure plan released by the Trump administration on February 12, 2018, drew immediate criticism as flawed because it did not adequately address the additional infrastructure improvement needed to increase US resilience (adaptation) to climate change.
If $2 trillion over the next eight to ten years, as estimated by ASCE, is a realistic picture of the shortfall, that means our near-term needs for annual infrastructure funding—not seriously considering the costs of global warming—are already between 5% and 6% of the total US federal budget. And infrastructure upgrading is by no means the only public cost associated with global warming adaptation. Public health protection, population relocations, and disaster relief are just a few of the functions where we can expect increased public expense.
It is not unreasonable to believe that we’ll be fighting a war of adaptation to climate change for the next 20 to 50 years. How do we estimate the cost of adaptation and raise the necessary federal, state, and local funds? And how much do we need to spend internationally to protect US overseas interests and prevent conflicts arising from, or being exacerbated by, climate change effects?
There are no easy answers. Companies and individuals sometimes have the foresight and resources to reserve funds or buy insurance, but they need better information to be able to determine how much of either or both. The US government has not typically built reserves to deal with future needs (anticipated or unanticipated), but rather has adopted a pay-as-you-go and borrow-as-you-must approach to everything from building infrastructure to social security to the costs of wars. State and local governments operate in much the same way, often with much tighter constraints on borrowing.
The best thing we can do now may be to develop, and continuously improve, several public and private cost scenarios to help us recognize the questions we’ll face. In particular, what new trade-offs will come up in the application of public funds? Is the demand likely to be for obvious adaptation expenses, such as increases in disaster relief expenditures, or it is likely to be cooked into other demands, such as increases in the costs for infrastructure maintenance and improvement?
An explicit public discussion of different cost scenarios would help build public understanding and flesh out possible responses. None of these discussions is complete, of course, without also considering the cost of not adapting. It is already politically difficult to invest in disaster prevention despite the saving that comes from such investment. This difficulty will almost certainly increase as global warming raises the stakes.
4. Strengthen policies and plans related to adaptation. There is a real risk that the nation will look back from 2040 and realize that its responses to the challenges of adaptation were too little, too late. Leaders need to increase the level of attention and resources dedicated to implementing and evaluating national, state, and local levels of preparedness. Policies and plans for risk management, crisis avoidance, and protecting vulnerable populations should be the focus of that effort.
For some federal government activities (e.g., flood insurance, disaster relief, and coastal military bases) the issues raised by global warming, and the requirements of adaptation, will be front and center in the coming decades. Public officials responsible for these activities are already planning for adaptation. For other federal activities (e.g., interstate transportation, border security, and international diplomacy) the requirements of adaptation to global warming are likely to be significant but, perhaps, not the most immediate concern in coming decades. Planning and preparation for adaptation might be more challenging in these agencies.
At the level of state and local public services—fire departments, policing, building codes and zoning, schools, water services and sanitation—exposures to the effects of global warming are very substantial. In response, some cities have established positions or offices focused on resilience. A few have started aggressively planning for adaptation to extreme climate change effects including heat events, droughts, and increased flooding. Concerns about flooding seem to be driving many of the adaptation leaders; coastal cities such as New York, Los Angeles, New Orleans, and Miami are in the vanguard, as are states with substantial coastlines such as California and Florida. This would be a good time to launch a serious national evaluation of US preparedness for the effects of global warming.
Although there is considerable uncertainty about specific effects, there is certainty that global warming is significant, accelerating, and seriously threatening. Doing nothing is not an option, as the cost of not adapting is many times greater than the cost of the most aggressive adaptation efforts. And even as we start now, we have to prepare for an extended effort. This is likely to be a marathon, not a sprint.
Human ingenuity has rescued our species from other dire situations. The green revolution saved us from widespread famine, and human ingenuity has conquered some diseases, such as polio, and increased life spans around the globe. Human ingenuity will also help us deal with climate change. As first steps, we need to be ingenious enough to develop more useful forecasts; invest in applied research for adaptation; plan for the costs and economic consequences of global warming; and strengthen policies for risk mitigation, crisis avoidance, and protection of vulnerable populations.