Depiction of Global Average Temperatures by NASA Jet Propulsion Lab

The UN has stated that the World must urgently act to cut a further 25% from predicted 2030 greenhouse gas (GHG) emissions. In the US, GHG emissions today are 4% above 1990 levels and are projected to increase. Based on UN goals, it appears that neither sufficient reductions in the release of GHG nor sufficient mitigations of the effects of climate change are taking place. To achieve those goals an 80% GHG reduction by 2100 would require an average reduction of 64 million metric tonnes each year for the next 82 years, or 165 million metric tonnes each year if the target date is 2050.

At the state level, even those jurisdictions that are concerned about climate change are falling short. These circumstances partially stem from a failure to appreciate the size and complexity of the issue as well as common disconnects between politics and technology. While many states have produced energy and emissions goals and mandates, the most important “figure-of-merit” is the rate at which GHG releases are abated. And while much of the focus has been the source of electricity generation, the biggest challenge to a low carbon future lies in the end use sectors.

We must recognize that 70-80% of the GHG releases come from the hundreds of millions of fossil fuel consuming “devices” in the transportation, residential, commercial, and industrial sectors. These will be far more difficult to fully replace than fossil fueled power plants. Replacing the country’s fossil fueled electricity with large nuclear plants would take about 320 such plants or about 250,000 three megawatt onshore wind turbines. By contrast, replacing fossil fueled end use items such as cars, hot water heaters, and space heaters would require hundreds of millions of replacements. There are about 250 million vehicles in the USA and about 130 million housing units. If each housing unit had an average of two fossil fueled appliances that would require 260 million replacements. Many more millions of replacements would also have to take place in the commercial sector.

Moreover, replacements for these end use appliances are typically powered with electricity. This could require new clean electrical capacity two or more times larger than today’s entire electric power system, plus vast amounts of energy storage. So, while many state energy goals are only directed at replacing fossil generation, achieving a low carbon future must also include serious policies addressing GHG emissions from end use sectors.

Click Here for a Table of Greenhouse Gas Release Rates