Greenhouse gas emissions are at record highs. The world's major emitters recently failed once again to reach an agreement to limit emissions. In the midst of all the gloom and doom, it is understandable that the International Energy Agency's latest World Energy Outlook has not received the attention it deserves.
But anyone seriously concerned about climate change needs to understand two fundamental constraints that emerge from this report. How we respond to these two constraints will determine if there is a reasonable way forward on climate change.
The first constraint has to do with trajectory of energy-related CO2 emissions required to keep the average temperature increase below the commonly accepted 2 degrees C threshold [PDF]. In the graph below, the IEA calls it the "450 Scenario" where the atmospheric CO2 concentration stays within 450 ppm.
It requires emissions to peak around 2017. By 2035, emissions in the 450 Scenario need to be just half of what we would have in the business-as-usual Current Policies Scenario. The difference between these two scenarios is as much as 22 Gt CO2 per year by 2035, about two-thirds of today's total energy-related CO2 emissions.
Before we ponder how to find those reductions with current and future energy technologies and efficiencies, here is the second constraint that makes the task even more difficult. If we take no further action by 2017 -- a likely situation -- emissions locked in by existing capital stock (such as power plants, buildings, factories, and vehicles) will use up the entire carbon budget for 2035, leaving no maneuvering space to achieve the 450 Scenario.
As the graph below shows, these locked-in emissions will ramp down as older capital stock is phased out over time, but all replacements and expansions will have to be zero carbon!
The IEA estimates that demand for primary energy will increase by one-third between 2010 and 2035, and 75 percent of all the energy will come from fossil fuels in 2035. The new BP Energy Outlook concurs with this trend and estimates an 81 percent share for fossil fuels in 2030. The 450 Scenario will be out of reach without rapid breakthroughs in renewable energy, battery technologies, biofuels, and carbon capture and storage (CCS). Unless, perhaps, if we are willing to think outside the box.
What if we could find practical and affordable emission reduction and sequestration opportunities outside of the energy realm that could offset a big part of fossil fuel emissions through 2035 and buy us the additional time needed for a full transition to clean energy?