Planetary climate pledge drive: Our view

For 22 years, the nations of the world have been discussing ways to prevent catastrophic damage to the Earth's climate caused by emissions of greenhouse gases.

And ever since the first United Nations' climate change convention in 1992, the globe has continued to warm as diplomats dickered in Kyoto (1997), in Copenhagen (2009), in Cancun (2010) and this year in Lima. According to the National Oceanic and Atmospheric Administration, 2014 is on track to be the planet's hottest year since modern record-keeping began.

About the best that can be said for the accord announced in Peru on Sunday, after two weeks of talks among nearly 200 nations, is that even a weak deal is better than no deal.

For the first time, all countries, including developing ones, committed to reduce the fossil fuel emissions that cause climate disruption. But the commitments — due during the first half of 2015 — won't be legally binding, and many are likely to be vague.

Put another way, the Lima agreement, designed to set the stage for a global pact in Paris next year, resembles a planetwide United Way drive. Everyone makes pledges; the follow-through relies mostly on peer pressure.

In this pledge-drive scenario, the most important commitments come from the top three emitters — China, the United States and the European Union. Together, they account for 52% of current carbon-dioxide emissions and 60% of cumulative emissions since the dawn of the Industrial Age. Here, there is a little more room for optimism:

• China (28% of current emissions, 11% of cumulative emissions) faces domestic unrest over poor air quality. It says it will reduce carbon emissions no later than 2030, make a big investment in renewable energy sources and explore setting up a nationwide "cap and trade" system that would put a price on greenhouse gas emissions.

• In the United States (14% current, 26% cumulative), President Obama has imposed the first binding limits on emissions from existing power plants, and he has agreed to cut U.S. pollution levels by 26%-28% below 2005 levels by 2025. These steps have made the U.S. less of an outcast at international climate talks but are under fire from congressional Republicans.

• The European Union (10% current, 23% cumulative) has set a goal of cutting its emissions 40% below 1990 levels by 2030.

The other hope outside the unwieldy U.N. climate negotiating system is technology. The cost of wind and solar energy has dropped sharply in the five years since the Copenhagen talks, raising prospects that renewables can displace at least some fossil fuels. Research also continues into ways to remove carbon from the atmosphere or bury emissions underground.

But those are uncertain, long-term possibilities. In the meantime, a certain amount of climate change is already baked in. The world has dallied so long that the goal of holding temperatures to 3.6 degrees Fahrenheit above pre-industrial levels might already be a lost cause.

As they look ahead to the next round of talks in Paris, the politicians have their timetable. The climate has its own.

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