The pace of global change poses multiple risks to communities and ecosystems, but also presents unprecedented opportunities to address those risks and cultivate a more resilient and prosperous future.
At the XLII (42nd) MIT Global Change Forum on March 28-29, more than 100 attendees from industry, academia, government and NGOs gathered at the Samberg Conference Center on the MIT campus to explore how global change is creating challenges and opportunities in agriculture, finance, energy, weather extremes, Earth-system thresholds (tipping points), and security. Facilitated by the MIT Joint Program on the Science and Policy of Global Change in an informal, “off-the-record” setting for independent assessment of studies and policy proposals, presentations and discussions examined impacts of global change in the broadest sense—not just from climate change but from a variety of causes.
“Since the inception of the Joint Program in 1991, we have always studied global change, but we focused largely on climate change in the early years,” said MIT Joint Program on the Science and Policy of Global Change Co-Director Ronald Prinn, a professor at MIT’s Department of Earth, Atmospheric and Planetary Sciences. “But as we evolved, we realized many phenomena, once studied alone, are in fact closely linked—as illustrated in our 2018 Food, Water, Energy and Climate Outlook—and no doubt we’ll go further in that direction.”
Here we summarize key points that emerged in presentations and discussions at this year’s Forum.
The first session highlighted challenges for the agriculture sector including a shrinking labor supply, the need for more efficient global trading schemes, and a trend toward greater diversity of food choices and consumer preferences. Opportunities are emerging from increased investment in robotics aimed at minimizing labor inputs and increasing predictability; gene editing to enable crops to resist disease and better tolerate drought or excessive moisture; and the use of big data to better inform management decisions. This explosion of agricultural innovation holds much potential for improving the quantity and quality of food.
As socioeconomic forces and innovation drive changes in this sector, agriculture is impacting—and impacted by—global environmental change. Agriculture, forestry and land-use account for nearly 25 percent of global greenhouse gas emissions that contribute to climate change, which, in turn, alters crop yields and increases demand for irrigation water in many regions. Other drivers of change in the complex agricultural system include population and income growth, which the Program’s 2018 Outlookprojects will increase demand for livestock and crops for livestock feed. The sector presents several opportunities where improved modeling could help decision-makers project crop yields, pinpoint the best places to grow crops, and identify climate adaptation responses.
The second session explored the need for a trillion-dollar global climate finance infrastructure to help countries pursue the mitigation and adaptation measures needed to build a low-carbon, climate resilient future. Key national challenges are to significantly increase finance flowing to low-carbon, climate-resilient activities, ensure that all finance flows across the economy in alignment with climate objectives, and increase the cost-effectiveness of low-carbon and climate-resilient investments. On the global level, the main challenge is not a lack of money, technology or innovation, but a strategy to apply those resources at the needed speed and scale. The opportunity is not only a more stable climate but also greater economic prosperity.
One approach to building a low-carbon future is to produce more electricity from nuclear reactors, but doing so would require overcoming substantial public opposition and costs. Any move toward deep decarbonization will likely increase efforts to bring more nuclear power plants online, especially advanced nuclear reactors that are more compact than today’s conventional models. The main financial challenge is to reduce the cost of construction, particularly of containment facilities. A combination of carbon pricing and dedicated government funding could overcome this challenge, thereby reducing risk to potential investors.
The third session began with an exploration of barriers to a high-renewable energy grid. While costs of renewables have decreased considerably in recent years, higher renewable penetration of the grid can only be achieved through greater flexibility in the physical and institutional systems that support it. The central challenge/opportunity is to develop both technical and market solutions to the problem of intermittency and electricity storage.
A high-renewable grid may only take the world so far toward the Paris Agreement’s long-term goal of keeping global warming below 1.5 degrees Celsius. Realizing that goal may require the deployment of a portfolio of advanced carbon dioxide removal (CDR) technologies such as bioenergy with carbon capture and storage (BECCS) and direct air capture (DAC) of CO2—each of which come with their own technical, economic and political challenges.
Projections of the energy mix for electricity generation on a 2°C emissions path must account for uncertainty in climate system parameters such as climate sensitivity to greenhouse gas (GHG) emissions and ocean heat uptake, and socioeconomic developments such as population and economic growth. Accounting for these uncertainties in an integrated manner, the Joint Program’s Integrated Global System Modeling (IGSM) framework projects that in 2100 the two largest sources of electricity generation will be natural gas with carbon capture and storage (CCS), and wind and solar; China will produce the largest share of the globe’s electricity; and the top two GHG-emitting sectors will be commercial and residential infrastructure, and agriculture.
Noting the increased vulnerability of society to heat waves, tropical cyclones and other extreme events, the fourth session examined the challenge of attributing extreme events to climate change, and of predicting how climate change will impact the frequency and intensity of such events.
A modeling approach developed at the Joint Program addresses the latter challenge by identifying large-scale atmospheric conditions associated with extreme events at local scales. In studies of past extreme events over different timeframes, this method has been shown to estimate the number of extreme events more consistent with observations than global or regional climate models. It also improves upon the capability of climate models to predict extreme events, particularly in model consensus studies.
Some of the largest climate impacts are expected to occur in developing countries, which have the least capacity to respond. Policy challenges for them include a lack of data and funding for adaptation measures. The opportunity is to channel traumatic extreme events into policy change and innovation, ensure that climate finance is used most effectively, and design resilience measures that reflect the interests of affected populations.
Defining a threshold as a “point above which something is true, and below which it is not,” the fifth session assessed the potential of some critical environmental thresholds to be breached. For instance, we are already crossing ocean thresholds with increased warming and acidity negatively impacting marine ecosystems including fish stocks. Reversing these trends will require sharp emissions reductions; adapting to them will require proactive marine management practices and sustained Earth-system observations.
When it comes to land-based vegetation ecosystems, it is difficult to predict if or when an irreversible threshold will be reached, and observations are limited. Such a capability would require long-term monitoring of several variables, including moisture- and drought-sensitivity, particularly in places where thresholds have already been exceeded. To avoid ecosystem collapse and build resilience, several measures can be taken that range from controlling invasive species to expanding protected areas.
Another key threshold is the point at which ice sheets in Greenland, Antarctica and elsewhere collapse and contribute significantly to sea-level rise. One may wonder, for example, how close we are to a tipping point for the West Antarctic ice sheet, and how to identify early warning signals. Much work is needed to better understand the physical mechanisms driving ice-sheet changes and thereby improve projections of ice-sheet collapse and associated sea-level rise.
Implications for security
The sixth and final session explored implications of global change for food, infrastructure, energy and national security. The latter topic was also the focus of the Forum’s keynote address.
Millions of people are food insecure, not because of limited global food supplies but due to restricted access to affordable, nutritious food. This limited access largely results from political unrest, war, climate change and poverty. One promising approach to reducing food insecurity in resource-limited countries and regions is to promote economic growth through development of the agriculture sector and food distribution infrastructure.
Protecting society from the impacts of extreme events requires moving from “one-size-fits-all” climate resilience programs to approaches that take into consideration the needs of the most socially vulnerable populations, from people of color to people with disabilities. Designing full-access resilience entails assessing the data on who is disproportionately impacted by potential extreme events, and including those populations in planning, response and recovery operations.
Efforts to advance clean energy penetration involves significant security risks. One key threat to the entire energy sector is foreign or domestic cyber activity. In the clean energy space, a major risk is significant dependence on imports of rare metals and minerals used to manufacture solar photovoltaic, wind generation and battery storage systems. Addressing these risks will require several measures, including developing rules of engagement for cyber-attacks; protecting supply chains for minerals and metals needed for wind, solar and batteries; supporting new domestic mining activities for key minerals and metals; and supporting innovation in using more earth-abundant materials for wind, solar and batteries.
On the national security front, several U.S. military installations lie within a short distance of a coastline, and have already been impacted by flooding linked to climate change. Others have altered their operations due to risks of exposure to wildfires, droughts and other extreme events. All of this impacts military readiness. One thing that may come as a surprise to many U.S. citizens is how embedded most military installations are in surrounding communities, and how dependent they are on those communities for energy, water and food. The U.S Department of Defense is now pursuing a stepped-up effort to boost resiliency and autonomy of its bases at home and abroad, including tests to determine how many hours these facilities can remain off the grid. In effect, these military installations serve as living labs for how communities across the country could become more climate resilient and energy efficient while cutting costs.