I. INTRODUCTION .................... 1455
II. COMMUNICATING CLIMATE CHANGE .................... 1458
III. DEMAND .................... 1461
IV. SUPPLY .................... 1466
V. INTERNATIONAL CONSIDERATIONS .................... 1472
VI. PLANETARY IDENTITY .................... 1476
In 1958, Charles David Keeling began measuring the concentration of carbon dioxide (CO2) in the atmosphere, at a site 11,000 feet above sea level near the top of Mauna Loa on the "big island" of Hawaii. The time series of monthly averages, the "Keeling Curve," is the iconic figure of climate change (see Figure 1). The curve oscillates and rises. The annual oscillations (whose details are seen in the Figure's inset) are the consequences of the seasonal breathing of the northern-hemisphere forests, which remove CO2 from the atmosphere during their growing season and return CO2 to the atmosphere as their leaves decay on the forest floor in winter. The steady rise - on average today, about 0.5% per year - is due primarily to the burning of fossil fuels. Indeed, the average rise would be twice as fast if all of the CO2 released during fossil-fuel burning stayed in the atmosphere. Roughly half of the CO2 emissions from burning fossil fuels stay in the atmosphere, one quarter go into the ocean (making it more acidic), and one quarter enter forests that, despite deforestation, are growing bigger.1
The era of consciousness of climate change began with Reeling's intrepid measurements.3 The seasonal oscillations in Figure 1 were unexpected, and it was soon clear that atmospheric CO 2 measurements were a new index of global human impact. The political message was that the global atmosphere mixes and retains a large part of the world's CO2 emissions, oblivious to what fuel is burned, in what country, and for what purpose. Again and again over the past fifty years, modelers have estimated future human emissions on the basis of assumptions about the economy and technology, while environmental scientists have gradually improved their ability to describe the likely consequences for global warming, sea-level rise, ecosystem disturbance, and hydrocycle disruption (storms, floods, droughts, etc.).
The landmark international treaty, the United Nations Framework Convention on Climate Change ("UNFCCC"), is often called the Rio Convention, because it was negotiated in Rio de Janeiro at the "Earth Summit" in June of 1992. As can be discerned from Figure 2, the rate of fossil fuel emissions almost tripled between 1958 and 1992 (from 8.5 to 22.7 billion tons of CO2 per year, an average increase of 2.9% per year for thirty-four years). By 2010, it had increased by another 40% (to 33.5 billion tons of CO2 per year, an average increase of 2.2% per year for eighteen years) and was four times larger than in 1958.4
I write soon after returning from "Rio + 20," a blockbuster United Nations event in June 2012 celebrating the twentieth anniversary of the Rio Convention. The mood in Rio was sober. United Nations diplomacy appeared to be shutting down. Judging from political rhetoric, discussion of climate change in the United States has already shut down. A premise of this Essay is that the current impasse has little social value. This Essay is about finding "restart buttons."
I am addressing "the environmental community," by which I mean all those who engage with environmental issues, notably climate change, whether professionally or simply because they find the issues compelling. The environmental community extends well beyond the environmental activist community and the environmental nongovernmental organizations. My assumption is that nearly all members of the environmental community, independent of where they stand on particular issues, feel frustrated by the current incoherent state of affairs and the lack of progress. The environmental community definitely includes me, which is why, below, I frequently refer to this community as "we. …