Here’s the frightening implication of a landmark study on carbon emissions: By 2018, no new cars, homes, schools, factories, or electrical power plants should be built anywhere in the world, ever again, unless they’re either replacements for old ones or carbon neutral. Otherwise greenhouse gas emissions will push global warming past 2˚C of temperature rise worldwide, threatening the survival of many people currently living on the planet.
Every climate expert will tell you we’re on a tight carbon budget as it is—that only so many tons of carbon dioxide can be pumped into the atmosphere before the global climate will overheat. We’ve already warmed temperatures 0.85˚C from pre-industrial levels, and the number rises every year. While no one thinks 2˚ C is safe, per se, it’s safer than going even higher and running the risk that global warming will spiral out of our control completely.
Last year, the latest Intergovernmental Panel on Climate Change (IPCC) report established a global carbon budget for the first time. It essentially stated that starting in 2014, the carbon we can afford is up to around 1,000 billion tons of CO2. In other words, our cars, factories, and power plants can only emit 1,000 billion tons (1,000 Gt, or gigatons) of CO2 into the atmosphere if we want to have a greater than 50/50 chance of keeping our climate below 2˚C of warming.
Even considering that humanity pumped 36 gigatons of CO2 into the atmosphere last year alone, 1,000 Gt still seems like a big budget. It might even seem like we have room to spare.
New research shows that we may not have been paying attention to the entire CO2 emissions picture. We’ve only been counting annual emissions, and not the fact that building a new coal or gas power plant is in reality a commitment to pumping out CO2 for the lifespan of a given plant—which usually ranges from 40 to 60 years. These future emissions are known as a carbon commitment.
A new study has tallied the carbon commitments from all existing coal and gas power plants by looking at their annual CO2 emissions and current age. The study assumes an operating life of 40 years. A 38-year old coal plant will have far smaller future CO2 emissions, and thus smaller carbon commitment than one built today. The study, “Commitment accounting of CO2 emissions,” determined that most new power plants that went online in 2012 have a very large carbon commitment—19 Gt of CO2.
Read the rest here (if you dare)
Update: belated h/t to Steve Mosher.