Update, Monday June 2: The new climate rules are out — here's our newest, updated overview of the new rules.
Next week is going to be a big one for US energy and climate policy. On Monday, June 2, the Obama administration will propose new rules to cut carbon-dioxide emissions from the nation's coal- and gas-fired power plants.
We're still awaiting further details on those regulations (see this post for a rundown of what we know so far). But we can start with a broader overview of the energy and climate context surrounding the debate.
Below are six charts and maps to get us started, looking at how the US electricity system is shifted in recent years — and what that has meant for climate change:
1) US carbon-dioxide emissions have fallen in recent years — but they're now rising again
This is arguably the key chart to understand Obama's broader climate agenda.
Since 2005, US carbon-dioxide emissions from energy sources have fallen roughly 10 percent. That's partly due to the massive recession. It's partly due to the fact that Americans are driving less. And it's partly due to the fact that cheap natural gas has replaced dirtier coal in the electricity sector.
But, for the White House, that's not enough. As part of the international climate talks, the Obama administration has pledged to reduce US emissions 17 percent below 2005 levels by 2020. So we're not quite there yet.
What's more, US carbon-dioxide emissions have started creeping upward again in 2013 and 2014 — in part because natural gas is getting more expensive and coal is making a comeback. So the Obama administration can't meet its climate goals unless additional changes happen.
2) Electricity is responsible for about 40 percent of US carbon-dioxide emissions
The data above is from 2012. Power plants that burned coal and natural gas for electricity made up about 38 percent of US emissions.
This also helps put Obama's new climate rules in perspective. Early reports suggest that the rules may force power plants to reduce their emissions by about 15 percent from 2012 levels.
If true, that would represent roughly 6 percent of all US emissions (and about 1 percent of global emissions). So clearly this EPA rule can't solve climate change on its own, although it would be a significant shift for the power sector.
3) Most of America's electricity still comes from coal and natural gas
Energy Information Administration
More specifically, here's where the United States got its electricity from in 2012:
Natural Gas 30%
Coal and natural gas are the major sources of emissions (and coal's the big one — releasing roughly twice as much carbon-dioxide per unit of electricity as natural gas). So any rule that targets those two energy sources is going to target a large and important source of US electricity.
Also note that coal has been declining in recent years in favor of somewhat cleaner natural gas — that's one big reason US carbon-dioxide emissions have been falling. (That said, there's a real question about whether the fracking boom is boosting emissions of methane, another potent greenhouse gas.)
Renewable sources like wind and solar, meanwhile, are growing very rapidly, but they've started from such a small base — so they still make just a tiny fraction of the overall electricity supply.
4) The electricity mix can vary wildly from region to region
This fact makes it even more complicated to regulate carbon-dioxide emissions from power plants. The Pacific Northwest, for instance, relies heavily on hydropower. Meanwhile, states like Ohio, Indiana, and West Virginia rely much more heavily on coal.
So a rule that makes sense for Oregon may not make as much sense for Ohio. The Environmental Protection Agency will likely have to take this into account when dealing with these rules.
5) Lots of US coal plants are getting retired
Back in 2011, there were 1,191 coal generation units operating in the United States. Since then, roughly one-quarter of them have either retired or are set to be retired. And hundreds of additional coal units are at risk of retirement in the years ahead.
There are two big reasons for this. The fracking boom has produced a glut of cheap natural gas. As a result, many power plant operators have found it uneconomical to continue operating their coal plants and are switching over to cheap natural gas. This has been a major factor in the decline of coal.
At the same time, new rules from the EPA on pollutants like mercury, sulfur-dioxide, and particulates are also putting pressure on utilities. Many plant owners may decide to shutter their older units rather than install costly new control technology. And that's before the upcoming rules on carbon-dioxide.
So when you hear people refer to the Obama administration's "war on coal," this is usually what they're referring to.
And what about electricity prices? So far, the coal-plant closures haven't had a huge effect on overall electricity prices — average retail prices have stayed flat for the last six years — in part because cheap natural gas has helped fill the void. But some experts have warned that electricity prices could well rise if natural-gas ever becomes more expensive (which has certainly happened in the past) and coal can no longer fill in the gap.
6) Meanwhile, global carbon emissions are rising fast…
Although carbon emissions have fallen in the United States, they're rising quickly in the rest of the world. And that means that global average temperatures are likely to rise more than 2°C over pre-industrial levels — a limit widely deemed unacceptable.
The United States can hardly tackle this problem on its own: the country is responsible for 17 percent of global carbon emissions. So even if this new EPA rule cuts emissions from power plants by the rumored 15 percent, that will still amount to just 1 percent of global emissions.
Obama administration officials, for their part, see these new rules as just one step in the ongoing international climate talks with countries like China and India. The idea is that if the United States can hit its 17 percent target by 2020, that will help push global talks forward — and they're optimistic about further progress, citing a recent breakthrough with China to curtail hydrofluorocarbons (HFCs), a potent greenhouse-gas.
Is that all feasible? It's hard to say — no one really knows yet what future international agreements on climate change will look like. But it's a reminder that these power plant rules certainly won't solve global warming on their own.