Getting Tough on Climate Pollution: Limiting Warming to 1.5

Melting and calving glaciers in the Arctic
Credit: all photos copyright 2018 David B. Goldstein

[updated January 2018]

This blog series is an effort to present some thoughts on how the U.S. and other nations could limit the increase in global average temperature to 1.5 C.  My goal is to spark a conversation on this critical issue.

Part 1 of a 3 part blog: Why limiting climate pollution is an economic development strategy

We have the technology and know-how to rein in climate change at a profit. In so doing, we can put millions of Americans to work where they live, with good middle class jobs, while making America stronger and more competitive globally.



The Paris Agreement established at the United Nations Framework Convention on Climate Change in 2015 sets a two-fold goal for the world’s nations: to hold the increase in global average temperature to "well below 2 degrees C" above pre-industrial levels and to pursue efforts to limit the increase in temperature to 1.5 C, “recognizing that this would significantly reduce the risks and impacts of climate change."

Limiting climate change to 1.5 degrees is a much-needed but previously unstated goal if the world is to avoid profound risks as well as the well-known costs and disruptions of severe climate change. Previous global climate accords had only included the goal of limiting climate disruption to 2 degrees, and numerous studies have provided detailed blueprints on how to reach this goal.

The changes required will reduce costs, create jobs, and help solve other environmental, economic, and health problems, and will improve the bottom line and quality of life for typical families and businesses.

What about 1.5 degrees? What would it take to hold the line there? This essay shows what sorts of policies we would need to get there if the U.S. decides to adopt this as its target, and how these policies would produce jobs in the sectors that need the most help, and would also improve economic justice. As of January 2018, 172 countries that represent 88 percent of global emissions, have formally joined the Paris Agreement. In addition, some more countries have signed and will officially join when they complete their domestic decision-making processes; these bring the total up to countries representing 97 percent of global emissions. (The remaining 3 percent of emissions come from shipping and aviation, which are out of the scope of the Agreement.)  So thought leadership on this issue is timely.


This essay has two goals:

  • to inspire policymakers to take the goal of limiting climate change to 1.5 seriously and undertake the bold and audacious steps needed to do this right away; and
  • to show that success is possible by explaining what it would require from a technology and behavioral point of view, and what it would produce in terms of economic development.

These steps are interconnected. No one will undertake assertive new policies if they don’t see convincing reasons why they will succeed. For example, one will not attract athletes to train for a marathon race if you tell them the goal is to run the race in one and a half hours. (The world record is 2:02:57, so the goal clearly is impossible.) But if you try to convince them that merely finishing a marathon is important, even if you do it walking, you are much more likely to motivate people.

Therefore this paper first discusses what it would take to limit climate change to 1.5 degrees. It does this in a U.S. context, where we will likely have to be at zero emissions, on a net basis, by 2050 or earlier. Other countries may have less aggressive goals in terms of absolute reductions, and may be able to continue growing emissions for a few more years before their peak. (China, for example, has committed to peaking its emissions by 2030 but may already be near the peak.) This is discussed in part 3.

What do the 2-degree scenarios show?

Two-degree scenarios, both global and U.S. domestic, show that the biggest single overarching strategy is to improve the efficiency of energy use: better cars, refrigerators, and lights, walkable neighborhoods that don’t require much car use, buildings that require much less energy to heat and cool, etc. This conclusion emerges whether the study was done by the International Energy Agency or by NRDC.

They also feature greatly expanded reliance on renewable energy sources, primarily wind and solar, which are integrated into large-scale electric grids that allow strong performance in one place to compensate for weak performance somewhere else on the grid.

Efficiency pays for itself several times over, reducing energy bills for families and businesses. These reductions are particularly important for lower income households. Efficiency also produces local jobs both directly and then as a result of consumers spending the money that they previously had wasted on things that they really want.

Strong efficiency policies can correct seven key economic imbalances that have plagued the American economy since 1973; thus they are a necessary part of economic growth and justice. It is interesting to note that the median income of an American family was rising steadily until 1973, when oil prices tripled. Starting then, the trend went flat, and the median household income basically has not risen since then. While other factors no doubt are also to blame, long-established trends such as growing median income do not just stop suddenly for no reason, and the reason they stopped in 1973 cannot be unconnected from the rise in oil prices. The oil crises of the 70s triggered the highest U.S.  inflation in a century, as well as leading to a trade deficit. Energy accounted for over 10% of GDP after the price increase, so energy prices are big enough to have triggered the change.

The continuing stagnation of median income after the effects of the second oil price rise of 1979 had faded away corresponds to a time of weakness in energy efficiency policy: after the bipartisan energy saving laws of the 70s, America saw a fading of the commitment to fuel economy standards, not only for cars but also for refrigerators, air conditioners, and whole buildings. Therefore this narrative strongly suggests that efficiency policies are one of the few consensus steps we can take towards improving economic justice.

Renewable energy costs about the same as polluting energy, but it protects us from fluctuating fuel prices. It also produces jobs and reduces pollution.

While the level of effort needed to reach the two degree goal is high, most of the work is done by policy makers or by the businesses that produce clean energy options, who profit from all that effort. Thus families will not notice much difference. And most of the difference is beneficial: expanded mobility choices and greater availability of housing in walkable, transit-served areas, less air and water pollution, and lower utility bills. And businesses will not see much in the area of increased challenges to running their operations.

The difficulties will be borne by government and private sector organizations that implement energy policies, or by energy efficiency companies that will need to be started or need to expand their scale of operation radically (with profits to match.) The only businesses that will be challenged in a major way are traditional energy suppliers, who will need to diversify out of many of their current offerings.

 Californians can take pride in the knowledge that their state is already on track to meet the two degree goal, and they haven’t really noticed the difference.  But perhaps they have noticed that the clean energy economy is helping California to create more jobs than the rest of the country. And the United States as a whole seems on track in 2016 with that year's emissions target (based on actual emissions inventories from 2014), in large part because of actions taken by the Obama Administration and by the states, even without a Congressionally approved climate goal. But on the other hand, forecasts for the year 2025 all agree that we will fall short of meeting our goals for limiting climate change to 2 degrees unless we do far more with policies.

The last two observations—that we are on track for our 2 degree goal in terms of recorded emissions but also falling off the track for 2025—point out the dualism that runs throughout this essay:

  • We can feel confident that we can meet bold and aggressive goals, because in the times and places where we have tried to meet them, we are succeeding; however
  • We need to do far more in terms of policies to reduce emissions, at the global, national, regional, state, local, and private-sector levels.  This needs to be a process of continual improvement, as outlined in the Paris Agreement, in which initial goals are set, progress towards meeting them is tracked, and the experience gained with what succeeds better than expected and what falls short leads us to refine our policies and meet more aggressive goals on the next iteration. We should ALWAYS expect that actions taken to date will not be sufficient to get to our ambitious goal for the future because we will ALWAYS need to be ready to take additional steps as we find additional opportunities. Even if action on the federal level remains gridlocked, the other channels for reaching success are still open, and if anything have been invigorated by the threat of U.S. federal government-level inaction.

In summary, most of the things we need to do to meet the 2 degree target are things that we should do for other reasons even if climate were not an issue. We would do them to save money, clean the air, protect wild places, create jobs, protect the poor from high energy bills, and encourage competition and innovation in the economy.

Almost all of the technology-based studies nationally and internationally stop at the savings needed to meet the 2 degree goal, concluding that it is not difficult to identify the technical measures needed and explain convincingly how they would be deployed. These studies also show that we do not need new technological breakthroughs. We can rely on technologies that can already be identified and in most cases even priced, sometimes with predictable incremental improvements over time, and policies that are known to work.

These analyses are presented in a variety of forms, starting with the International Energy Agency’s Energy Technology Perspectives, a technical/policy report updated annually, and continuing with a number of other studies written by academic institutions and nonprofit organizations.

NRDC issued a comprehensive report in 2017 that shows in great detail how America could meet its accepted share of a 2-degree goal, and this essay relies heavily on the analysis and results of that report.

One key conclusion of the report is that the measures used to meet it—primarily enhanced investment in clean energy—are essentially cost-free and produce hundreds of thousands of new jobs on net. This result can be obtained almost entirely by using tools and technologies we have at our fingertips today.

Thus it is widely accepted that the world knows how to meet a 2 degree target with economically logical technologies and with policies that have a record or success. Mobilizing these actions at scale and securing the political will to get it done will require sustained effort over many years. It won’t be easy, but if it were easy it would already be done.

Part 2 of this essay discusses what it will take to limit warming to 1.5 degrees.

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