29/02/2016

Will We Ever Stop Using Fossil Fuels?

Massachusetts Institute of Technology - Peter Dizikes | MIT News Office

Not without a carbon tax, suggests a study by an MIT economist.
Christopher Knittel


In recent years, proponents of clean energy have taken heart in the falling prices of solar and wind power, hoping they will drive an energy revolution. But a new study co-authored by an MIT professor suggests otherwise: Technology-driven cost reductions in fossil fuels will lead us to continue using all the oil, gas, and coal we can, unless governments pass new taxes on carbon emissions.
"If we don't adopt new policies, we're not going to be leaving fossil fuels in the ground," says Christopher Knittel, an energy economist at the MIT Sloan School of Management. "We need both a policy like a carbon tax and to put more R&D money into renewables."
While renewable energy has made promising gains in just the last few years — the cost of solar dropped by about two-thirds from 2009 to 2014 — new drilling and extraction techniques have made fossil fuels cheaper and markedly increased the amount of oil and gas we can tap into. In the U.S. alone, oil reserves have expanded 59 percent between 2000 and 2014, and natural gas reserves have expanded 94 percent in the same time.
"You often hear, when fossil fuel prices are going up, that if we just leave the market alone we'll wean ourselves off fossil fuels," adds Knittel. "But the message from the data is clear: That's not going to happen any time soon."
This trend — in which cheaper renewables are outpaced by even cheaper fossil fuels — portends drastic climate problems, since fossil fuel use has helped produce record warm temperatures worldwide.
The study concludes that burning all available fossil fuels would raise global average temperatures 10 to 15 degrees Fahrenheit by the year 2100; burning oil shale and methane hydrates, two more potential sources of copious fossil fuels, would add another 1.5 to 6.2 degrees Fahrenheit to that.
"Such scenarios imply difficult-to-imagine change in the planet and dramatic threats to human well-being in many parts of the world," the paper states. The authors add that "the world is likely to be awash in fossil fuels for decades and perhaps even centuries to come."
The paper, "Will We Ever Stop Using Fossil Fuels?," is published in the Journal of Economic Perspectives. The authors are Knittel, who is MIT's William Barton Rogers Professor in Energy; Michael Greenstone, the Milton Friedman Professor in Economics and the College at the University of Chicago; and Thomas Covert, an assistant professor at the Booth School of Business at the University of Chicago. The scholars examine costs over a time frame of five to 10 years, stating that further forecasts would be quite speculative, although the trend of cheaper fossil fuels could continue longer.

More efficient extraction
At least two technological advances have helped lower fossil fuel prices and expanded reserves: hydraulic fracturing, or fracking, which has unlocked abundant natural gas supplies, and the production of oil from tar sands. Canada, where this type of oil production began in 1967, did not recognize tar sands as reserves until 1999 — an energy-accounting decision that increased world oil reserves by about 10 percent.
"There are hydrocarbons that we can now take out of the ground that 10 or 20 years ago we couldn't," Knittel observes.
So whereas some energy analysts once thought the apparently limited amount of oil reserves would make the price of oil unfeasibly high at some point, that dynamic seems less likely now.
To see how much better firms are at extracting fossil fuels from the Earth, consider this: The probability of an exploratory oil well being successful was 20 percent in 1949 and just 16 percent in the late 1960s, but by 2007 that figure had risen to 69 percent, and today it's around 50 percent, according to the U.S. Energy Information Administration.
As a result of these improved oil and gas extraction techniques, we have consistently had about 50 years' worth of accessible oil and natural gas reserves in the ground over the last 30 years, the scholars note.
All told, global consumption of fossil fuels rose significantly from 2005 through 2014: about 7.5 percent for oil, 24 percent for coal, and 20 percent for natural gas. About 65 percent of global greenhouse gas emissions are derived from fossil fuels, according to the U.S. Environmental Protection Agency. Of those emissions, coal generates about 45 percent, oil around 35 percent, and natural gas about 20 percent.

Renewable hope
To be sure, renewable energy has seen an impressive decline in its prices within the last decade. But looking at the "levelized" cost of energy (which accounts for its long-term production and costs), solar is still about twice as expensive as natural gas. The need to handle sharp evening increases in power consumption — what energy analysts call the "duck curve" of demand — also means power suppliers, already wary of solar power's potential to reduce their revenues, may continue to invest in fossil fuel-based power plants.
The development of better battery technology, for storing electricity, is vital for increased use of renewables in both electricity and transportation, where electric vehicles can be plugged into the grid for charging. But the example of electric vehicles also shows how far battery technology must progress to make a large environmental impact. Currently only 12 percent of fossil fuel-based power plants are sufficiently green that electric vehicles powered by them are responsible for fewer emissions than a Toyota Prius.
Alternately, look at it this way: Currently battery costs for an electric vehicle are about $325 per kilowatt-hour (KwH). At that cost, Knittel, Greenstone, and Covert calculate, the price of oil would need to exceed $350 per barrel to make an electric vehicle cheaper to operate. But in 2015, the average price of oil was about $49 per barrel.
"It's certainly the case that solar and wind prices have fallen dramatically and battery costs have fallen," Knittel says. "But the price of gas is a third almost of what it used to be. It's tough to compete against $1.50 gasoline. On the electricity side … the cheap natural gas still swamps, in a negative way, the cost of solar and even wind."

Emphasizing the case for a carbon tax
That may change, of course. As Knittel observes, new solar techniques — such as thin-film layers that integrate solar arrays into windows — may lead to even steeper reductions in the price of renewables, especially as they could help reduce installation costs, a significant part of the solar price tag.
Still, the immediate problem of accumulating carbon emissions means some form of carbon tax is necessary, Knittel says — especially given what we now know about declining fossil fuel costs.
"Clearly we need to get out in front of climate change, and the longer we wait, the tougher it's going to be," Knittel emphasizes.
Knittel supports the much-discussed policy lever of a carbon tax to make up for the disparity in energy costs. That concept could take several specific forms. One compelling reason for it, from an economists' viewpoint, is that fossil fuels impose costs on society — "externalities" — that users do not share. These include the increased health care costs that result from fossil fuel pollution, or the infrastructure costs that are likely to result from rising sea levels.
"Taxes on externalities are not inconsistent with the free-market system," Knittel says. "In fact, they're required to make the free-market system achieve the efficient outcome. This idea that a pure free-market economy never has taxes is wrong."
Knittel adds: "The point of the paper is that if we don't adopt policies, we're not leaving fossils fuels in the ground."

Links

Scientists Settle On Low End Of Carbon Budget Spectrum

Climate Home - Alex Pashley

Economies must decarbonise rapidly to avert dangerous warming, say scientists (credit: UN)


Countries agreed last year to limit global warming to 2C this century and "pursue efforts" to hold it to 1.5C to avoid dangerous climate change.
Scientists have come up with a range of estimates for the cap on greenhouse gas pollution needed to have a likely chance of avoiding that threshold. It's known as the "carbon budget".
A review of the evidence on Wednesday published in journal Nature Climate Change recommended dismissing the more generous allowances.
From 2015 onwards, there is only room for another 590-1,240 gigatons of carbon dioxide equivalent, it found. That includes other gases like ozone, methane, and nitrogen dioxide.
Some studies have put the upper limit as high as 2,390 GtCO2. But the report authors said those figures were not robust as they did not account for all greenhouse gases or had other methodological limitations.The findings add urgency to international effort to curb global emissions, which stood at 40Gt CO2e in 2014 and at current rates will eat up the budget within 15-30 years. It requires overhauling centuries of fossil fuel-based development and the swift adoption of clean energy technologies.
"We have figured out this budget is at the low end of what studies indicated before, and if we don't start reducing our emissions immediately, we will blow it in a few decades," said Joeri Rogelj at the Vienna-based International Institute for Applied Systems Analysis, who led the study.
"[M]any different factors can lead to carbon budgets that are either slightly smaller or slightly larger. We wanted to understand these differences, and provide clarity on the issue for policymakers and the public."

Links

Six Burning Questions For Climate Science To Answer Post-Paris

The Conversation -       

We still don't know enough about questions such as where the tipping points are for Arctic ice melt. Christine Zenino/Wikimedia Commons, CC BY

Much has been written about the challenge of achieving the targets set out in the Paris climate agreement, which calls for global warming to be held well below 2℃ and ideally within 1.5℃ of pre-industrial temperatures.
That's the headline goal, but the Paris agreement also calls for a strong focus on climate science as well as on curbing greenhouse emissions. Article 7.7c of the agreement specifically calls for:
Strengthening scientific knowledge on climate, including research, systematic observation of the climate system and early warning systems, in a manner that informs climate services and supports decision-making.
The next paragraph also calls on countries to help poorer nations, which have less scientific capability, to do the same.
But what are the many elements of climate science that need strengthening to achieve the aims of the Paris agreement? Here are six questions that need answers.

What do the targets mean?
What do the 2℃ and 1.5℃ targets imply for our climate and adaptation responses? Even warming of 2℃ will have significant impacts for humans and natural systems, albeit much less than would occur if we allowed warming to continue unchecked. Still, climate science needs to clarify what is gained by meeting the 1.5℃ and 2℃ targets, and the consequences of missing them.

Are we on track?
It will be essential to monitor the climate system over the coming years and decades to see whether our efforts at curbing warming are delivering the expected benefits, or if more measures are needed.
The path to these ambitious temperature targets will not be smooth – there will be periods of rapid warming interspersed with periods of slower warming. We will not meet the targets if the world relaxes on mitigation efforts because of a short-term slowing in the rate of warming as a result of natural variability, such as we saw between 1998 and 2013.
Greenhouse gas concentrations, global temperatures, rainfall and water balance changes, extreme weather events, ocean heat content, sea level and terrestrial and marine carbon sinks are all vitally important elements to track. A focus on surface temperature alone is not sufficient.

What are the tipping points in the climate system?
Tipping points are thresholds beyond which there will be large, rapid and possibly irreversible changes in the climate system. The Greenland and Antarctic ice sheets are one example – beyond a certain level, warming will cause large and irreversible loss of ice, and sea level rise of many metres over the ensuing centuries. Thresholds also exist for ecosystems, such as the Great Barrier Reef, and the services they provide, including food production and water supply.
We need to know what these thresholds are, the consequences of crossing them, and how much and how fast we will have to reduce emissions in order to avoid this.

How will climate and extreme events change?
Many places already experience weather extremes such as heatwaves, droughts, fire, floods, storm surges and cyclones, all with damaging consequences. Many of the negative impacts of climate change will occur through changes in the magnitude, duration and frequency of these extreme events.
To adapt to these changes and manage the risks, more detailed information is needed on local and regional scales. It is important to recognise that 2℃ of globally averaged warming does not imply 2℃ everywhere (many regions, particularly on land, will have larger temperature rises). Extremes may increase faster than averages.
We also need to understand the short-term (decades) and long-term (centuries) implications of choices made today.

What are the appropriate adaptation pathways?
Even if the Paris targets are achieved, some adaptation will be essential. So how do we reduce vulnerability, minimise costs and maximise opportunities? Given the changes already observed with the roughly 1℃ of global warming so far, it's fair to say that more severe impacts will occur during this century.
Keeping warming within 2℃ and moving to a lower-carbon world presents many challenges. Considerable work will be needed to help identify climate-resilient pathways and allow humans to adapt to the changes.
Successful adaptation will require an ability to foresee and prepare for inevitable changes in the likelihoods of extreme climate events from year to year. Development of climate forecasts on timescales of a year to decades may provide opportunities to reduce losses in critical sectors such as water, agriculture, infrastructure, tourism, fisheries, energy and natural resources.

Can we take greenhouse gases back out of the atmosphere?
Most scenarios for future emissions that keep warming below the agreed Paris target require not just a reduction in emissions, but also the ability to reduce greenhouse gas concentrations in the atmosphere – so-called "negative emissions".
One proposed method of partially meeting our energy needs and reducing CO₂ concentrations is called BioEnergy Carbon Capture and Storage. It would involve growing biofuels for energy, then capturing and burying the carbon dioxide released by these fuels. While potentially important, its large-scale deployment poses important questions regarding its costs and benefits and how the large amount of agricultural land required would compete with food production to feed the world's growing population.
To keep climate change below 2℃, some have proposed a need for more radical geoengineering options if emissions are not phased out quickly enough. These include schemes to cool the Earth by reducing solar radiation. But these proposals fail to address other knock-on issues of carbon dioxide emissions, such as ocean acidification. They also pose large risks, are beset with ethical issues and beg the question of who is going to take responsibility for such schemes.
The Paris agreement proves that the world's nations know we need strong climate action. But society faces tough choices as we seek to find economically, socially and environmentally feasible ways to meet the targets. Informed decisions will depend on robust science at both local and global scales, which means that far from being done, climate science is now more important than ever.

Links