News and Outreach: Henry Jacoby

Ben Geman
National Journal

Don't expect too much from the global climate-change accord that's expected to emerge from high-stakes international talks in Paris next year.

A new MIT study concludes that even if negotiators reach a deal at the United Nations conference, it probably won't be enough to limit global temperature increases to 2 degrees Celsius above pre-industrial levels. That's the level many scientists say would help stave off some of the most dangerous and disruptive effects of climate change.

Here's the study's bottom line on what to expect from the so-called Conference of the Parties 21 in Paris: "Based on our expectations for the architecture of a COP-21 agreement, and our predictions about the national contributions likely to come forth under it, our analysis concludes that these international efforts will indeed bend the curve of global emissions. However, our results also show that these efforts will not put the globe on a path consistent with commonly stated long-term climate goals," states the paper by economics professor Henry Jacoby and Y-H Henry Chen, who both work with MIT's Joint Program on the Science and Policy of Global Change.

The 2°C ceiling has been highly optimistic for a while, as global greenhouse-gas emissions continue to soar.

[Read more...]

Laura Barron-Lopez
The Hill | Energy & Environment

Negotiations among global leaders in Paris next year meant to mitigate climate change and keep the global temperature below 2 degrees Celsius are likely to fail, according to a new study.

The Massachusetts Institute of Technology (MIT) report released Wednesday, concludes that the outcome of next year's United Nations (UN) talks in Paris probably won't put the globe on the path to limiting temperature increases to 2 degrees Celsius.

The researchers looked at the major players in the talks from the U.S, to China and European Union. The report details the steps each has taken to fight climate change and the emissions reductions they are working to set individually to model what a final agreement might look like.

U.S. involvement in any future climate work, is "crucial," the report states. It adds that the deal reached next year can be expected to "bend the curve of global emissions but will not put the globe on the path consistent with commonly stated long-term climate goals."

The report also states that the negations between leaders over the next 18 months heading into the talks will "heavily" influence global greenhouse gas emissions as far out as 2045 or 2050.

"We see emissions increasing through 2030 and, without additional international agreement, continuing to increase in the following decades," said MIT economics professor Henry D. Jacoby in a questionnaire accompanying the study. "That raises the question, if it’s obvious in the early stages of the negotiation that we’re not getting on a path to temperature goals, what will be the nature of the follow-up process? We should be starting to have that discussion as well."

President Obama will attend a UN climate summit in New York next month to help build momentum for the talks in Paris. The administration's climate agenda at home and abroad faces harsh criticism from Republican lawmakers who oppose the president's domestic regulations.

Opponents of climate policies argue that regulations on U.S. power plants will have little if any impact on global emissions, and would hurt the economy.

But since the administration's proposed the new carbon pollution standards on existing power plants, Environmental Protection Agency chief Gina McCarthy has said the rules are "internationally changing the tone of the conversation."

Joint Program codirector emeritus Henry Jacoby appeared on CBC's The Lang & O'Leary Exchange to discuss the findings of the Third National Climate Assessment. Jacoby is a lead author of the report's chapter on mitigation. Watch the interview below. 

Environmental controls designed to prevent leaks of methane from newly drilled natural gas wells are effective, a study has found — but emissions from existing wells in production are much higher than previously believed.

The findings, reported today in the Proceedings of the National Academy of Sciences1, add to a burgeoning debate over the climate impact of replacing oil- and coal-fired power plants with those fuelled by natural gas. Significant leaks of heat-trapping methane from natural gas production sites would erase any climate advantage the fuel offers.

One concern is the potential release of methane during hydraulic fracturing, or 'fracking', which uses injections of high-pressure fluids to shatter rock and release trapped gas. Before production can commence, the well must be 'completed' by removal of the fracking fluids, which contain gas that can escape to the air.

To test the effectiveness of current controls, the researchers installed emissions-monitoring equipment at 27 wells during their completions in 2012 and 2013. Their results suggest that current controls reduce emissions in such wells by 99% compared to sites where the technology is not used, says lead author David Allen, an engineer at the University of Texas in Austin.

The researchers' estimate of annual emissions from wells undergoing completion, 18,000 tonnes per year, is also roughly 97% less than the estimate given in 2011 by the US Environmental Protection Agency (EPA).

Less encouraging was what the team discovered at 150 other well sites that were already producing natural gas. Such wells often use pneumatic controllers, which siphon off pressurized natural gas from the well and use it to operate production-related equipment. "As part of their normal operation, they emit methane into the atmosphere," Allen says.

His team's work suggests that emissions from pneumatic controllers and other equipment at production wells is between 57-67% higher than the current EPA estimate. However, the study also finds total methane emissions from all phases of natural gas production to be about 2.3 million tonnes per year, about 10% lower than the EPA estimate of 2.5 million tonnes…More.

Henry Jacoby, an economist and former director of the Joint Program on the Science and Policy of Global Change at Massachusetts Institute of Technology in Cambridge, agrees. "This is important work," he says, "but the great bulk of the problem is elsewhere, downstream in the natural gas system", including poorly capped oil and gas wells no longer in production.

Read the complete article here.

Reprinted by permission from Macmillan Publishers Ltd: Nature (doi:10.1038/nature.2013.13748), Copyright 2013.
Photo Credit: Steve Starr/Corbis

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Climate change seems like this complicated problem with a million pieces. But Henry Jacoby, an economist at MIT's business school, says there's really just one thing you need to do to solve the problem: Tax carbon emissions.

"If you let the economists write the legislation," Jacoby says, "it could be quite simple." He says he could fit the whole bill on one page.

Basically, Jacoby would tax fossil fuels in proportion to the amount of carbon they release. That would make coal, oil and natural gas more expensive. That's it; that's the whole plan.

Jacoby's colleague John Reilly told me the price of gasoline might rise by 25 cents a gallon in the first year. Over time, that would increase. By 2050, Reilly figures the carbon tax would add about $1 to the price of every gallon. Across the economy, prices of energy-intensive goods and services would rise. This would encourage people and businesses to be more efficient.

This is why economists love a carbon tax: One change to the tax code and the entire economy shifts to reduce carbon emissions. No complicated regulations. No rules for what kind of gas mileage cars have to get or what specific fraction of electricity has to come from wind or solar or renewables. That's by and large the way we do it now.

Reilly says the current web of rules is a more complicated and more expensive way of getting the same outcome as a carbon tax. The current system "pretty much is one of the worst ways we could do it," he says.

As with any fix for climate change, a carbon tax would hit some people harder than others. People with long commutes would pay more. People who work in coal mines could lose their jobs.

But here is where Reilly brings up what is perhaps the most surprising thing about a carbon tax: If you do it right, he says, carbon tax can be nearly painless for the economy as a whole. 

Besides reducing carbon emissions, a carbon tax brings in a bunch of money – it's a tax after all. So, Reilly says, you can reduce, say, income tax to balance out the new taxes people are paying for carbon emissions. People pay more for gas, but they get to keep more of their income.

I called around and talked to a bunch of economists about this, and they said the basic idea was sound: If you give the carbon-tax money back by cutting income taxes, you can probably offset a lot of the pain.

President Obama has indicated he would support a market-based solution to climate change. But a carbon tax would of course require an act of Congress. And right now, that seems unlikely.

By: Joel Kirkland and Peter Behr

June 26, 2013

President Obama's plan to use a mixture of mandates and flexible regulation to cut greenhouse gas emissions is being viewed by energy industry experts through an age-old axiom: The devil is in the details.

The plan appears to be a shot in the arm for natural gas, as Obama's proposed regulation of carbon dioxide emissions from existing coal-fired power plants would provide a boost to cleaner-burning gas generators.

The White House's second-term climate agenda faces daunting head winds. Opposition from Republicans and resistance from coal-state Democrats, and the nuts and bolts of crafting a policy that would mark a significant shift for the nation's electric power industry, are immediate hurdles. Court challenges could create a protracted process for regulating carbon, as it has for U.S. EPA regulations of toxic air pollutants pushed through by the Obama administration.

But the daily stir of coal, natural gas and electricity markets in the United States also matters. With details of the new carbon policy still to come, unpredictable market prices will continue to be an underlying driver of decisions by electricity producers about where to invest and what energy sources to dispatch. Abundant coal will battle it out with growing shale gas production, several experts interviewed by EnergyWire predicted.

"There is no disagreement that the environmental regulations, many of which were proposed during the Bush administration, are going to bind and cause several -- tens of gigawatts -- of coal plants to be uneconomic," said Jay Apt, director of the Electricity Industry Center at Carnegie Mellon University. "If gas prices stay reasonable, then people will be buying gas plants. 

Obama rolled out his climate plan in the blistering summer heat. Yesterday's speech on a Georgetown University quad rested on the premise that rising concentrations of heat-trapping gases in the atmosphere are the result of industrial emissions and that unregulated U.S. power sector emissions are contributing too much to rising temperatures.

The White House directive for EPA to begin drawing up a proposal to regulate existing coal-fired power plants had already been set in motion. In 2007, the Supreme Court ruled that EPA could not sidestep its authority to regulate emissions tied to climate change. The agency later issued an "endangerment finding" that created a legal foundation for regulating carbon. 

"We limit the amount of toxic chemicals like mercury and sulfur and arsenic in our air and water, but power plants can still dump unlimited amounts of carbon pollution into the air for free," Obama said in the speech. "That's not right, that's not safe, and it needs to stop."

Carbon economics

How you get there might be left up to the most unpredictable factor of them all: the economy.

"If you want to stabilize the concentration of carbon dioxide in the atmosphere, you need a substantial reduction of emissions," Apt said.

"Meeting greenhouse gas targets in a flat-growth economy, where the industrial use of electric power is the same now as it was in the early 1990s, is very different than a scenario in which you blithely say growth is going to be 3 percent a year," he said.

A range of factors affect the immediate future of electric power generation, said Metin Celebi, a principal with the Brattle Group. "The most important one is the gas price relative to the coal price," Celebi said.

The future direction of that price is anyone's guess, given how many questions remain about the pace of shale gas production.

Of the nation's approximately 300 GW of coal-burning power generation capacity, nearly 40 GW was targeted for retirement by 2016, according to a Brattle analysis.

More "lenient" regulatory controls, along the lines expected from the Obama administration, could cause that total to rise to nearly 60 GW, the Brattle report says. A very strict policy could raise that to 77 GW of coal plant capacity retirements.

Lower gas prices plus strict regulations could cause almost half of the U.S. coal fleet to retire, a scenario that Celebi and his colleagues concluded in an October 2012 report would likely be untenable for electricity producers.

This shift is occurring for both short-term price and longer-range policy reasons that are not easy to separate. Most energy companies expect that at some point, an explicit or implicit price will be placed on power plant carbon emissions, and that particularly burdens coal plants, whose carbon footprint is twice that of efficient gas generators, said Katherine Spector, executive director of commodities strategy for CIBC World Markets Corp.

That expectation affects companies' decision on retiring or retaining older, inefficient coal plants. "It's actually a combination of the two" -- price and policy -- "and the policy environment could significantly accelerate the trend," Spector said.

The drop in natural gas prices over the past two years has tilted production in gas's favor, particularly in competitive power markets where the two kinds of power plants seek low-bid opportunities to run hour by hour.

Until shale gas production flattened gas prices, coal held a solid lead. In April 2011, coal-fired plants accounted for 41 percent of electric power output, compared to 23 percent for natural gas. A year later, the two fuels' shares were almost identical. Then gas prices moved up again from less than $2 per thousand cubic feet to $4 recently, and coal made a comeback. Its share of electricity production was 38 percent this April compared to 26 percent for gas.

But an expectation of relatively cheap gas also affects decisions on the future of coal plants. "It is a different world in gas prices than we had three or four years ago," Celebi said. "Gas price projections have come down substantially, and that's something you can put more weight on."

The Energy Information Administration, the statistical arm of the Energy Department, noted in its 2013 annual energy outlook that "the interaction of fuel prices and environmental rules is a key factor in coal plant retirements."

For all the price and production scenarios EIA considered, less than 15 GW of new coal-fired capacity would be added between 2012 and 2040. "For new builds, natural gas and renewables generally are more competitive than coal, and concerns surrounding potential future GHG [greenhouse gas] legislation also dampen interest in new coal-fired capacity," EIA said.

Shutting one-third of coal

A 2012 paper by a team led by Massachusetts Institute of Technology researcher Henry Jacoby said the increased gas supply boosts the power industry's flexibility to meet baseload electricity demand if expectations about nuclear power don't pan out or coal retirements speed up.

Under an aggressive policy to slash carbon that requires a 50 percent emissions reduction below 2005 levels by 2050, there would have to be "substantial changes in energy technology."

If the development of shale gas became too expensive, gas use would "grow slightly for a few decades." Toward the end of that period, however, "it would be priced out of this use because of the combination of rising producer prices and the emissions penalty."

Renewable energy would grow to 29 percent of power demand, and coal would keep a substantial position in the power pie. 

Fact sheets issued by the administration yesterday left crucial questions about the policy plans unanswered, noted ClearView Energy Partners, "especially the threshold levels of emissions that will govern new and existing [generation] units."

On a back-of-the-envelope assessment, ClearView said that if the administration adopts a formula proposed by the Natural Resources Defense Council calling for a limit of 1,500 pounds of CO2 equivalent per megawatt-hour of electricity production, it could add another 70 GW of coal plant retirements by 2020. That's on top of the 40 GW of expected retirements tied to current EPA rules on mercury emissions and air toxins, the ClearView analysis said. 

"In the aggregate, this adds up to a shutdown of roughly one-third of U.S. coal-fired generating capacity within the space of a decade," ClearView said. "Program design matters, too. The inclusion of offsetting emissions reduction mechanisms could keep more coal online."

Republicans in Congress have accused the Obama administration of threatening grid reliability through its pressures on coal-fired generation.

Celebi said that remains a big question. "It depends on where and when those plants retire," he said. "If it's a long period of time, the markets will have a chance to respond by cutting consumption or adding other resources. 

"If it's too much, too quick, that will not be feasible," he said. 

State foot-dragging

Politics soured the policy debate starting in 2009, electricity demand declined as the economy slumped, and natural gas prices fell to record lows in 2012.

Meanwhile, the technology-driven onshore drilling boom has turned up a "bridge fuel" to cleaner forms of electricity. And the White House has been openly supporting gas's role in combating climate change and spurring economic growth, despite concerns about methane emissions -- a potent greenhouse gas -- tied to upstream gas production.

"Sometimes there are disputes about natural gas," Obama said yesterday. "But let me say this: We should strengthen our position as the top natural gas producer because, in the medium term at least, it not only can provide safe, cheap power, but it can also help reduce our carbon emissions."

For electric utilities, the latest White House climate plan comes nearly four years after a bruising period of political wrangling over carbon cap-and-trade legislation. In 2009, the Edison Electric Institute was mired in the details of a bill that would distribute emissions credits for power generators to buy and sell under a carbon pollution cap. EEI's Tom Kuhn, president of the trade group of investor-owned utilities, had put together a fragile coalition of companies that could support the approach to ratcheting down emissions.

The premise behind the coalition-building had been that it's better to have a "market-based" program shaped by Congress than to leave it to top-down EPA regulations under the existing Clean Air Act.

The House passed the cap-and-trade bill by a slim margin in the summer of 2009, a signature achievement for House Democrats, but one that rested on compromises too politically hot for the Senate. The divisive debate revved up an opposition campaign targeting the science and politics of climate change. Republican leaders used the defeated legislation as a cudgel in the 2010 elections.

Since then, EPA has continued to tighten rules around conventional pollutants. New plants will have to comply with Mercury and Air Toxics Standards (MATS) rules. Other regulations addressing water intake and cooling water discharge are also shaping utility industry plans. Conventional coal gradually is being forced out of power portfolios.

Also on the table is an EPA draft rule that would cap carbon emissions at 1,000 pounds per megawatt-hour of generation for newly built power plants. The standard, which encourages fuel-switching to gas, would put the kibosh on new coal-fired power plants.

In a prepared statement after the president's speech yesterday, EEI's Kuhn urged EPA to put in place measures that "contain achievable compliance limits and deadlines" and "are consistent with the industry's ongoing investments to transition to a cleaner generating fleet and enhanced electric grid." 

"It is also critical that fuel diversity and support for clean energy technologies be maintained, not hindered," Kuhn added.

The slowdown in electricity demand in the United States has helped enable efficiency technology and power plant retrofits to control pollution. But analysts and executives from powerful utilities like Georgia-based Southern Co. and Ohio-based American Electric Power Co. Inc. have said carbon limits pose the biggest risk to their coal fleet. 

State utility commissions responsible for regulating power plants could slow the shift to low-carbon standards, analysts said. 

"There will be litigation and foot-dragging on the part of some states in developing implementation plans," said Adele Morris, an energy economist at the Brookings Institution. "I think EPA is in the early stages of what they would even propose."

By Henry (Jake) Jacoby 

Introduction

Mitigating climate change doesn’t sound as monumental as ending, or reversing climate change. But with global phenomenon already “contributing to the deaths of nearly 400,000 people a year and costing the world more than $1.2 trillion… annually,” according to the Climate Vulnerability Monitor, MIT professor Henry “Jake” Jacoby explains why efforts to mitigate climate change may be crucial to determining the next generation’s quality of life.

Henry (“Jake”) Jacoby is William F. Pounds professor emeritus in the MIT Sloan School of Management, and former co-director of the MIT Joint Program on the Science and Policy of Global Change.

Talking about mitigating climate change risk is a bit like the story of the man arrested for murder whose lawyer said to him, “I’ve got good news and bad news. The bad news is the blood found at the crime scene matches your DNA. The good news is your cholesterol level is down to 160.”

First, the bad news about climate change: The quantity of greenhouse gases humans have pumped into the atmosphere since the dawn of the industrial age is already changing the earth’s climate and raising global temperatures. What’s not widely recognized is that simply stabilizing global greenhouse gas emissions at today’s levels will not stabilize their atmospheric concentrations and effects on climate. Much deeper cuts will be required. Moreover, even if we succeed in reducing future emissions drastically, our children and grandchildren will have to live with the consequences of global warming –not just higher temperatures, but more severe storms, sea level rise, fire, drought and other environmental changes.

With no additional mitigation policy, we estimate there’s about a 50/50 chance that global temperatures will rise by as much as 5 degrees Celsius by the end of this century. There’s almost a one in four chance global temperatures will rise by 6 C or more.

Over the past two decades, diplomats have tried to negotiate a deal to limit atmospheric concentrations of “Kyoto gases” (carbon dioxide, methane, nitrous oxide and other industrial gases). Their ultimate goal: to curb global temperature increases to 2 C by the year 2100. However, after analyzing the data, the objective looks daunting.

Whatever we and the other nations do, climate change will adversely affect future generations. By steadily pressing ahead to create a non-carbon-based economy by whatever means available, we can limit the damage.

For example, one specific target is to limit atmospheric concentrations to about 450 parts per million (ppm). But given that the concentration of these gases has already risen from 275 ppm in the late 18th century to around 440 ppm today, and is climbing steadily, it’s doubtful we can achieve that goal.

But all is not lost. According to our calculations at MIT’s Joint Program on the Science and Policy of Global Change, even if we limit atmospheric concentrations of the Kyoto gases to a more modest 650 ppm, the high-end risks of climate change — temperature increases of 5 to 7 C — disappear. In other words, our grandchildren would still have to live with the disruptive effects of climate change, but they wouldn’t have to face the most catastrophic scenarios.

That’s the good news about climate change: almost anything we do to limit greenhouse gas emissions has its biggest effect on the worst possible outcomes. That’s why it’s worth keeping up the fight to reduce greenhouse gas emissions even though some targets will be hard to meet.

Here in the U.S., despite the national gridlock on climate change policy, energy-related carbon dioxide emissions have dropped in recent years — in part because of the recession but also due to a shift from coal to natural gas as a power source. The fact that President Obama talked about climate change in his inaugural address, plus the effect of recent storms and drought on public understanding of the risk, may help shift the debate toward a more aggressive policy response.

Right now, the U.S. has a cobbled together quilt of state, regional and national policies — automobile mileage standards, appliance efficiency ratings, renewable energy subsidies — that indirectly limit greenhouse gas emissions. From an economic perspective, the cheapest and best way to reduce emissions would be with a carbon tax, or a cap-and-trade system that places a price on carbon emissions. It’s a win/win/win solution. It would 1.) lower greenhouse gases emissions and oil imports, 2.) increase revenue which could be used to cut other taxes, and 3.) have a neutral-to-positive effect on economic growth. If a price penalty for emitting greenhouse gases is not politically feasible, then more expensive regulatory measures are going to be the way forward.

Whatever we and the other nations do, climate change will adversely affect future generations. By steadily pressing ahead to create a non-carbon-based economy by whatever means available, we can limit the damage.

By: Vicki Ekstrom

Fatih Birol, chief economist of the International Energy Agency (IEA), visited MIT on Wednesday, November 28 to present this year’s World Energy Outlook. While on campus, Birol met with researchers at the Joint Program on Global Change to learn about the latest developments on climate change policy and MIT’s Emissions Predictions and Policy Analysis (EPPA) model. The model is used by MIT researchers to make their own world economic and emissions projections.

“We had a very productive discussion about the future of the world’s energy system development and advances in modeling alternative pathways. We also shared information about our current projects and future directions,” said Sergey Paltsev, assistant director for economic research at the MIT Joint Program on Global Change, after the meeting. “IEA’s World Energy Outlook is one the most comprehensive and authoritative sources in energy projections and related carbon emissions.”

Birol also commented on the usefulness of the exchange:

"As our World Energy Outlook 2012 shows, the global energy system is undergoing fundamental, rapid change. MIT's proven, interdisciplinary approach to research and education in energy and climate issues will be even more important in the years to come,” Birol said.

Named by Forbes magazine as one of the most influential people on the global energy scene, Birol chairs the World Economic Forum’s Energy Advisory Board and is often called on to brief high-level political figures — including President Barack Obama.

Birol’s meeting with Paltsev, along with MIT Global Change researchers Henry Jacoby and Valerie Karplus, came prior to an MIT Energy Initiative-hosted event on the IEA’s World Energy Outlook. The Outlook projects that the United States will become the world’s leading oil producer within a few decades, while gas will continue to be a major player. It also turns attention to climate change.

“As each year passes without clear signals to drive investment in clean energy, the ‘lock-in’ of high-carbon infrastructure is making it harder and more expensive to meet our energy security and climate goals,” said Birol when IEA released the Outlook on November 9.

The Outlook finds that four-fifths of the total energy-related carbon emissions permitted under a scenario that limits warming to 2°C, the globally-agreed goal, are already locked-in by existing capital stock such as power stations, buildings and factories. It warns that without further action by 2017, the energy-related infrastructure in place would generate all the carbon emissions allowed up to 2035. Delaying action is a false economy, the report says, noting that for every $1 of investment in cleaner technology that is avoided in the power sector before 2020, an additional $4.30 would need to be spent after 2020 to compensate for the increased emissions.

Read more about the Outlook in a special MIT News interview with Fatih Birol here.

By: Washington Post/Associated Press

The issue:

People love to talk about the weather, especially when it’s strange like the mercifully ended summer of 2012. This year the nation’s weather has been hotter and more extreme than ever, federal records show. Yet there are two people who aren’t talking about it, and they both happen to be running for president.

Where they stand:

In 2009, President Barack Obama proposed a bill that would have capped power plant carbon dioxide emissions and allowed trading of credits for the right to emit greenhouse gases, but the measure died in Congress. An international treaty effort failed. Obama since has taken a different approach, treating carbon dioxide as a pollutant under the law. He doubled auto fuel economy standards, which will increase the cost of cars but save drivers money at the pump. He’s put billions of stimulus dollars into cleaner energy.

Mitt Romney’s view of climate change has varied. In his book “No Apology,” he wrote, “I believe that climate change is occurring” and “human activity is a contributing factor.” But on the campaign trail last year he said, “We don’t know what’s causing climate change on this planet.” He has criticized Obama’s treatment of coal power plants and opposes treating carbon dioxide as a pollutant and the capping of carbon dioxide emissions, but favors spending money on clean technology. Romney says some actions to curb emissions could hurt an already struggling economy.

Why it matters:

It’s worsening. In the U.S. July was the hottest month ever recorded and this year is on track to be the nation’s warmest. Climate scientists say it’s a combination of natural drought and man-made global warming. Each decade since the 1970s has been nearly one-third of a degree warmer than the previous one.

Sea levels are rising while Arctic sea ice was at a record low in September. U.S. public health officials are partially blaming unusually hot and dry weather for an outbreak of the deadly West Nile virus that is on pace to be the worst ever. Scientists blame global warming for more frequent weather disasters, with the World Health Organization saying: “Climatic changes already are estimated to cause over 150,000 deaths annually.” Others put the toll lower.

Emissions of carbon dioxide and other greenhouse gases from the burning of fossil fuels are trapping more of the sun’s heat on Earth. One study showed that 97 percent of the scientists who publish about climate in peer-reviewed journals say global warming is man-made. So do just about every major science society and institution that has weighed in.

But limiting carbon dioxide emissions from coal and oil would be costly, with billions of dollars in changes to the U.S. economy only a starting point. Similarly the price of not doing anything is extraordinarily high because of costly and deadly extreme weather. People will pay either way in taxes, energy prices, insurance premiums, disaster relief, food prices, water bills and changes to our environment that are hard to put a price tag on, says MIT economist Henry Jacoby.

A NASA study this year found the most extreme type of weather, which statistically should happen on less than 0.3 percent of the Earth at any given time, is now more common. Until recently, the most extreme year was in 1941 when extremes covered 2.7 percent of the globe. From 2006 to 2011 about 10 percent of the globe had that extreme weather, with a peak of 20 percent, the study said. That was before this year’s record extremes started.

The issue of man-made global warming is “totally missing” from the campaign between Obama and Romney, says Jacoby. It should be talked about, he says, because “we’re running a serious risk of passing a much-damaged planet to our descendants.”

By: Richard Harris

Listen to the story.

SOURCE: Keith Srakocic/AP

The boom in cheap natural gas in this country is good news for the environment, because relatively clean gas is replacing dirty coal-fired power plants. But in the long run, cheap natural gas could slow the growth of even cleaner sources of energy, such as wind and solar power.

Natural gas has a bad rap in some parts of the country, because the process of fracking is not popular. But many people looking at cheap natural gas from the global perspective see it as a good thing.

Henry Jacoby, an economist at the Center for Energy and Environmental Policy Research at MIT, says cheap energy will help pump up the economy.

"Overall, this is a great boon to the United States," he says. "It's not a bad thing to have this new and available domestic resource." He says cheap energy can boost the economy, and he notes that natural gas is half as polluting as coal when it's burned for electricity.

"But we have to keep our eye on the ball long-term," Jacoby says. He's concerned about how cheap gas will affect much cleaner sources of energy. Wind and solar power are more expensive than natural gas, and though those prices have been coming down, they're chasing a moving target that has fallen fast: natural gas.

"It makes the prospects for large-scale expansion of those technologies more chancy," Jacoby says.

Natural Gas: 'A Bridge To Nowhere'?

From an environmental perspective, natural gas could help transition our economy from fossil fuels to clean energy. It's often portrayed as a bridge fuel to help us through the transition, because it's so much cleaner than coal and it's abundant. But Jacoby says that bridge could be in trouble if cheap gas kills the incentive to develop renewable industry.

"You'd better be thinking about a landing of the bridge at the other end. If there's no landing at the other end, it's just a bridge to nowhere," he says.

In the short run, at least, the wind industry isn't too worried about this. Denise Bode, who heads the American Wind Energy Association, says low gas prices don't undercut current prices for wind, because those are mostly fixed by 20-year contracts, not market prices.

And even if wind is a bit more expensive than natural gas, she says utilities still want it in their mix. Windmills aren't subject to changing fuel prices, so the cost of production is quite predictable. That's not true for natural gas — there's no guarantee that today's cheap prices will stay as low as some predict.

"It's very difficult to really know how certain that is, so you always want to balance that with something that is certain," Bode says.

Reducing Political Will For Renewables?

What really worries her isn't natural gas — it's politics. Wind could lose a huge tax break at the end of this year. And that would have a much more dramatic effect than low natural gas prices.

"You'll see very low numbers" for new wind installations if the federal production tax credit expires," Bode says. "In fact, I think EIA [the U.S. Energy Information Administration] projects almost zero for 2013."

The solar industry's subsidies run for several more years, so they are not in that bind, at least not yet. But Trevor Houser, an energy analyst at the Rhodium Group, says these tax credits and other incentives like state renewable standards are key if renewables are to grow and mature during the natural-gas glut.

"Long-term renewable deployment in the U.S. is going to depend primarily on policy," Houser says. "Is there enough concern about environmental consequences to put in place incentives for renewable energy?"

That partly depends on how much of a premium people and companies will be willing to pay for cleaner energy. Right now, with natural gas so cheap, that premium is fairly substantial.

"If those prices hang around for another three or four years, then I think you'll definitely see reduced political will for renewable energy deployment, " Houser says. "But we don't expect prices that low to hang around that long, because low prices are in many ways self-correcting."

Gas is so cheap now that companies that produce it are struggling to make a profit. So Houser expects prices to move up. That will help close the price gap between gas and renewable energy.

Even so, there's still a huge way to go before prices and government policies do enough to significantly reduce emissions of the gases that contribute to global warming.