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Alli Gold Roberts
MIT Joint Program on the Science and Policy of Global Change

China is the world’s second largest national economy and its largest exporter. This growth has come at a cost, with energy demands and associated environmental damages on the rise. China is now the world leader in consumer energy use and CO₂ emissions. As countries around the globe work to reduce carbon emissions, policymakers are interested in measuring and ultimately reducing emissions associated with the relocation of industry and manufacturing overseas.

In a study released in the March issue of Energy Economics, researchers at Tsinghua University and MIT developed a new model to determine if policy proposals could help reduce carbon emissions associated with goods exported from China.  They found that taxes on energy-intensive exports and policies encouraging the Chinese economy to shift from industry to services are ineffective in significantly reducing total CO₂ emissions, because the same goods would still be produced elsewhere. 

“Developed countries are discussing the possibility of imposing a trade tariff on emissions embodied in imported goods in an effort to prevent the relocation of high-emitting industries overseas and to shore up domestic competitiveness,” says Tianyu Qi, a PhD student at Tsinghua University and the lead author of the study.  “It is important to understand how vulnerable the Chinese economy is to such a policy.”

Approximately 22 percent of China’s CO₂ emissions are the result of net exports.  These emissions are categorized as “trade-embodied” emissions because they are produced as a result of goods and services that are exported.

In their analysis, the researchers considered the impacts of two policies that are similar to measures included in China’s Twelfth Five-Year Plan. The first policy is a tax on energy-intensive exports and the second policy involves incentivizing a shift in China’s economy away from industry and towards services.

“In exploring these policies—both of which are advertised as carbon-reducing strategies—we find that neither would have a significant impact on total global emissions because reduced production in China is partially offset by increased production elsewhere,” says Qi, also a researcher with the MIT-Tsinghua China Energy and Climate Project.

If policymakers want to simply reduce emissions associated with China’s trade, the researchers suggest policies that support economic structural changes.

“A policy that targets the expansion of domestic demand, along with a shift toward services, is more effective at reducing China’s export-embodied CO₂ emissions,” says Valerie Karplus, co-author of the study and the director of the Tsinghua-MIT China Energy and Climate Project. “This will in turn reduce China’s exposure to potential tariffs on embodied carbon imposed overseas.”

Karplus explains that such a move is not a long-term solution to reducing CO₂ emissions and would ultimately shift production of many industrial products to other nations—shifting emissions along with them.

The researchers also find that the EU, the U.S. and Japan are the largest net recipients of trade-embodied CO₂ emissions. In addition, the researchers expected energy-intensive industries such as steel and aluminum production to be responsible for most of the CO₂ emissions associated with China’s trade, but instead they found the production of machinery and equipment to be the main culprit.

“This because China exports large volumes of machinery and equipment products, such as refrigerators and televisions, even though commodities such as aluminum and steel are more CO₂-intensive than these products,” explains Niven Winchester, an environmental economist in MIT’s Joint Program on the Science and Policy of Global Change and a co-author of the study.

To analyze the impact of policies on CO₂ emissions, the MIT-Tsinghua China Energy and Climate Project developed a new model called the China-in-Global Energy Model, or C-GEM. C-GEM disaggregates China’s 30 provinces and details the entire energy system. The model also includes global trade data to measure the interactions between China and the global economy.

The Tsinghua-MIT China Energy and Climate Project is a collaborative effort between the MIT Joint Program on the Science and Policy of Global Change and the Institute for Energy, Environment and Economy at Tsinghua University in Beijing, China. This group is working to analyze the impact of existing and proposed energy and climate policies in China on technology, energy use, the environment and economic welfare.

Michael Davidson
MIT-Tsinghua China Energy and Climate Project

According to tallies by the National Energy Administration, China added 14 gigawatts (GW) of grid-connected wind power capacity in 2013, now the fifth consecutive year with installs of over 10 GW (here, at a glance, is China’s grid in 2013). Over the same time period, wind curtailment – or, spilled wind, which is when the grid operator tells wind farm operators to reduce output because of reliability or other constraints – has become one of two sore spots, together with grid connection, for the otherwise booming sector (read more background on both topics). Official estimates now available of wind curtailment in 2013 show some improvements over 2012, though the problem is far from solved.

As in previous years, northeastern provinces with large coal-fired power capacities and the transmission-constrained northwestern region topped the list for curtailed wind. Inner Mongolia is part of two separate grid regions: the northwest (W. IMAR) and the northeast (E. IMAR). In the figure, I show the actual capacity factor as well as its reduction compared to the potential capacity factor according to official curtailment statistics.

Measuring curtailment is particularly tricky, because once turbines are slowed or halted it is difficult to reconstruct what the wind power production would have been otherwise. Comparing to the U.S., which consistently has an edge in terms of utilization of its wind turbines, China’s wind farms are under-performing, even after correcting for curtailment. This is largely attributed to different quality in components, though inaccurate curtailment numbers may also play a role. Collectively, this has led to the third year in a row of the unfavorable situation of China leading the world in wind capacity yet still trailing in terms of generation.

Approvals for new wind in some of the provinces heaviest hit by curtailment (Heilongjiang, Jilin, Inner Mongolia and Yunnan) are now being held up as the central government reconsiders how to divvy up its renewable subsidies and promote the sector most efficiently. Following a shake-up by the State Council last March, the central planning agency, the National Development and Reform Commission (NDRC), in theory gave up approval authority to the provinces, after only receiving it two years prior. However, currently, a “makeshift plan” which still incorporates centrally-administered annual targets is being implemented to transition to a more market-based approach.

On the other side of the spectrum, the capacity factor of thermal power (of which coal was 95% of generation in 2012) maintained historically low levels in 2013. Coal’s precipitous decline in the U.S. following the shale gas boom has led to a reduction in capacity factor of 14 percentage points here. Yet, whereas new coal builds in the U.S. are stagnant, China’s decrease has occurred amidst continued capacity expansion.

In these low utilization provinces, there is increasing evidence that China’s coal-fired power sector is overbuilt. In Jilin, for example, a wind-rich northeastern province, coal plants generate at less than 40% of their capacity even as coal capacity doubled from 2008-2011. The Jilin government is expediting approvals for large energy consumers and subsidizing their electricity bills above baseline in an attempt to pick up the slack.

Critically, overcapacity when coupled with China’s generation cost recovery mechanisms and constraining minimum outputs for thermal generators may mean less integration space for renewables—as I explained before here.

The China Electricity Council, in its 2014 projections and recommendations, called out the northeast’s excess capacity problem, recommending that the central government “strictly control” new coal and wind construction in the region. It projected a smaller (though still substantial) increase in coal-fired capacity nationwide of 30 GW. CEC’s other projections for new installs in 2014 (my calculation based on the current 2013 capacity figures): 23 GW hydro, 17 GW wind, 14 GW solar, 6 GW nuclear, and 5 GW gas.

Read the rest of the story here.

 

By Genevieve Wanucha
Oceans at MIT

Water has a lot of say in how Earth’s climate works. And scientists often acknowledge that the uncertainty about climate’s future trajectory comes from a lack of understanding of water. This intellectual challenge filled the better part of February 10-12 for 37 leading climate researchers and graduate students and postdoctoral fellows who participated in the Lorenz Center’s first scientific workshop, “Water in the Climate System,” at the MIT Endicott House in Dedham, Massachusetts.

The Lorenz Center is a new climate research initiative founded by MIT professors Kerry Emanuel and Daniel Rothman in the Department of Earth, Atmospheric, and Planetary Sciences as a way to renew the emphasis on fundamental questions about climate. The founders dedicated the center to the late MIT professor Edward N. Lorenz, the architect of chaos theory, who shared their conviction that a better description of the underlying principles in climate will make the complex system easier to understand.

Some of the biggest names in climate-related fields presented work on climate and hydrological mechanisms to an audience packed with inquiring minds. Sessions included “Convection,” “Water Vapor, Clouds, and Climate,” “Moisture and Weather,” “Precipitation and Climate,” and “Potpourri,” an eclectic mixture of aquaplanet modeling and geomorphology. All 26 presentations are available in slide format here.

“It was a great opportunity for younger scientists to learn about the big ideas in the field and hear from voices outside of MIT,” says MIT PhD student Tim Cronin. In every discussion period, to avoid the “experts-talking-to-experts” phenomenon, Emanuel asked the graduate students and postdocs to pose the first few questions. This approach made the newer generation of researchers more than mere observers, and their questions drove the conversation, animating the experts in intense discussions of the major climate conundrums of our time: How do ocean and atmosphere circulations transport heat across the globe? How can we design models that accurately estimate regional changes in the water cycle as the globe warms? When can we expect significantly different summers and snowstorms?

This workshop was made possible by a generous gift from Colin Masson, a retired astrophysicist who appreciates the Lorenz Center’s broad view of climate science and who attended the event. Private donations like Masson’s support the Lorenz Center’s regular activities, which also include the annual John Carlson Lecture. To reach their ultimate vision, Emanuel and Rothman are currently raising funds to support graduate students, postdoctoral researchers, and visiting scientists with backgrounds in diverse areas such as applied mathematics, biology, and chemistry.

“Our idea, simply put, is both to attract the very best minds to climate science and to give them free rein to think creatively, unsaddled by the pressing practical demands of climate forecasting,” the founders write in "A Fresh Approach to Climate Science" (pdf). If the “Water in the Climate System” workshop was any indication, the Lorenz Center is already a magnet of basic research talent.

Alli Gold Roberts
MIT Joint Program on the Science and Policy of Global Change

By the late 1990s, scientists had observed more than two decades of rapid global warming, and expected the warming trend to continue. Instead, despite continuing increases in greenhouse gas emissions, the Earth’s surface temperatures have remained nearly flat for the last 15 years. The International Panel on Climate Change verified this recent warming “hiatus” in its latest report.

Researchers around the globe have been working to understand this puzzle—looking at heat going into the oceans, changes in wind patterns, and other factors to explain why temperatures have stayed nearly stable, while greenhouse gas concentrations have continued to rise. In a study published today in Nature Geoscience, a team of scientists from MIT and elsewhere around the U.S. report that volcanic eruptions have contributed to this recent cooling, and that most climate models have not accurately accounted for the effects of volcanic activity.

“This is the most comprehensive observational evaluation of the role of volcanic activity on climate in the early part of the 21st century,” says co-author Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT. “We assess the contributions of volcanoes on temperatures in the troposphere—the lowest layer of the atmosphere—and find they’ve certainly played some role in keeping the Earth cooler.”

There are many components of the Earth’s climate system that can increase or decrease the temperature of the globe. For example, while greenhouse gases cause warming, some types of small particles, known as aerosols, cause cooling. When volcanoes erupt explosively enough, they enhance these aerosols—a phenomenon referred to as “volcanic forcing.”

“The recent slowdown in observed surface and tropospheric warming is a fascinating detective story,” says Ben Santer, the lead author of the study and a climate scientist at Lawrence Livermore National Laboratory. “There is not a single culprit, as some scientists have claimed. Multiple factors are implicated. The real scientific challenge is to obtain hard quantitative estimates of the contributions of each of these factors to the so-called slowdown.”

The researchers verified the cooling phenomenon by performing two different statistical tests to determine whether recent volcanic eruptions have cooling effects that can be distinguished from the intrinsic variability of the climate. The team found evidence for significant correlations between volcanic aerosol observations and satellite-based estimates of both tropospheric temperature and sunlight reflected by the particles off the top of the atmosphere.

“What’s exciting in this work was that we could detect the influence of the volcanic aerosols in new ways. Using satellite observations confirmed the fact that the volcanic particles reflected a significant amount of the sun’s energy out to space, and of course losing energy means cooling—and the tropospheric temperatures show that too,” explains Solomon, who is also a researcher with MIT’s Joint Program on the Science and Policy of Global Change. “There are still uncertainties in exactly how big the effects are, so there is more work to do.”

Alan Robock, a professor of environmental sciences at Rutgers University and a leading expert on the impacts of volcanic eruptions on climate, says these findings are an important part of the larger climate picture. “This paper reminds us that there are multiple causes of climate change, both natural and anthropogenic, and that we need to consider all of them when interpreting past climate and predicting future climate.”

“Since none of the standard scenarios for evaluating future global warming include volcanic eruptions,” Robock adds, “this paper will help us quantify the impacts of future large and small eruptions when they happen, and thus better interpret the role of humans in causing climate change.”

This research was led by a team at Lawrence Livermore National Laboratory and builds upon work Solomon conducted in 2011, finding that aerosols in an upper layer of the atmosphere—the stratosphere—are persistently variable and must be included in climate models to accurately depict climate changes.

The research was supported by the U.S. Department of Energy.

In climate change, science and policy are inextricably linked—more so than in most contemporary social phenomena. The complexity of understanding earth’s systems generates uncertainty, which feeds into an imperfect policy process that often warps ideal economic instruments beyond recognition. Without clear recognition of this linkage, the resulting mixture is frequently less than appetizing. ­­This January, we continued an MIT Joint Program on the Science and Policy of Global Change tradition of presenting to the MIT community the basics (and some of the nuance) of this complex issue over a two-session Independent Activities Period (IAP) course.

While the minutiae of a 3-dimensional atmosphere and ocean model may be daunting (and require clusters of networked high-performance computers to complete a run), it turns out we can understand a lot about climate change from simplified models that build on basic physics accessible to any first-year undergraduate. Fundamental principles, such as energy balance, yield straightforward arguments about why the Earth should warm as we add greenhouse gases to its atmosphere. Those same principles can also be used to frame simple predictions about how future warming might proceed—information that policymakers and analysts can use to help plan for the future.

Considering climate change as an “externality” (a cost imposed on society by individuals and companies without compensation), economists have developed theories of how to reduce environmental impacts by appealing to pocketbooks. Putting a price on pollution (e.g., carbon tax) or selling and trading “rights” to pollute (e.g., cap-and-trade) are two common policy levers to encourage polluters to cut back while lessening the overall economic impact. When we couple our global climate models with global economic models (collectively, the Integrated Global System Modeling framework – IGSM), we can better understand the complex interactions between human activities and earth system changes.

We are invariably asked: Do we prefer to tax or to trade? Strictly economically speaking, if we have perfect information on the damages from climate change and the costs required to mitigate, the two should be equivalent. However, accounting for uncertainties on both ends of the human-earth interaction, we find that our answer from a strictly modeling perspective depends on which we can estimate better: the social cost of carbon (the total cost to society of the externality) or the “tipping point” thresholds of irreversible climate change? This is an area of ongoing research.

Policy-makers tend to respond to what they can see, an important part of the policy-science nexus of climate change. Typhoon Haiyan, which devastated the Philippines last November, stood as a stark reminder of the human suffering from extreme weather events—as did Hurricanes Sandy and Katrina on the domestic front. Hitting land just as the annual UN climate talks opened in Poland, Haiyan (or Yolanda, in the Philippines) became an impetus for international efforts there to create the beginnings of a “Warsaw Mechanism”, an international compensation scheme for loss and damage resulting from climate change. Predicting how the frequency and severity of such storms will change in a warming world is a crucial research focus, particularly as society builds more densely along coasts and in floodplains and exposes itself to more potential economic and personal loss.

Ultimately—unlike the Earth’s orbit—no policy issue exists in a vacuum. As we described examples of current efforts in the US, China and the EU to reduce greenhouse gas emissions, it is rare that the best of both science and economics are captured by policies in practice. The prevailing politics have a large impact on where the needle lands—tax, trade or other—and indicate an even bigger challenge that lay before us, not as scientists but as citizens.

Daniel Rothenberg and Daniel Gilford are graduate students in MIT’s Department of Earth and Planetary Sciences. Michael Davidson and Arthur Yip are graduate students in MIT’s Engineering Systems Division.

Genevieve Wanucha
Program in Atmospheres, Oceans and Climate

IAP 2014 was bone-chilling, and thanks to 12.310, An Introduction to Weather Forecasting, 20 new amateur forecasters can tell you why.

Always offered between semesters, 12.310 reveals the principles of fluid dynamics that govern the atmosphere’s movement. In lectures, real forecasting exercises, and a trip to WBZ TV’s on-air weather center, students learn where newsrooms get their daily weather predictions — and how they can make their own.

“Our aim is that students come to understand that weather forecasting is not guessing and is based on real science,” says Lodovica Illari, senior lecturer in synoptic meteorology in MIT’s Program for Atmospheres, Oceans, and Climate (PAOC), who has taught the course for 20 years. “We hope the students get interested in fluid dynamics and come back and do some more.”

To reveal the laws governing the atmosphere’s motion “in action,” Illari used demonstrations with MIT’s Weather in the Tank materials. In one class, Illari rotated a cylindrical tank of water on a turntable to emulate the dynamics of Earth’s atmosphere. A bucket of ice at the tank’s center created a temperature gradient. As students peered in, Illari dropped ink into the water to make visible the small currents forming in the water, demonstrating the conditions that create weather systems.

12.310 stands as a yearly reminder of MIT’s distinguished history in weather forecasting. In fact, Carl-Gustaf Rossby, who transformed weather forecasting into an atmospheric science, founded the country’s first meteorology program at MIT in 1928. A line of prominent MIT faculty meteorologists followed, including Jule Charney, Norman Phillips, Victor Starr, and Edward Lorenz. The fundamental contributions to fluid dynamics made by these past professors resonate in MIT’s modern-day research into much longer-time-scale atmospheric phenomena such as climate.

As the students of 12.310 learned the basics of weather forecasting, they came to appreciate an insight of Professor Lorenz’s that changed meteorology forever. At MIT in 1961, Lorenz found that rounding a few digits off one decimal number in a computer weather simulation changed its projected long-term pattern. He had discovered the big implications of the chaos theory principle of “sensitive dependence on initial conditions” for weather prediction. Slightly imprecise measurements, even single-digit differences in dew point, can skew long-term forecasts. The chaotic nature of short-term weather places a limit of less than 10 days on accurate forecasts.

To make their own forecasts, the students used raw data spit out of weather prediction models run at the National Weather Service, which are read out in maps of the temperature, air pressure, dew point, wind, and moisture across the country. With that information, the students anticipated the likely passage of warm or cold weather fronts by searching for regions of strong gradients in temperature or moisture and shifts in wind direction. The class ended with a TV-style presentation of the day’s weather and a Boston weather forecasting competition. This year, Fiona Paine ’17 took home the prize of a digital indoor/outdoor thermometer.



The course was organized and taught by Illari and co-instructor Jeff Scott, a research scientist at PAOC and the Center for Global Change Science, along with teaching assistants Casey Hilgenbrink ’15 and PAOC graduate student Vince Agard ’11, who are both members of the MIT Weather Forecasting Team.



Many of the undergraduates signed up for 12.310 to get a taste of the kind of science they could pursue in PAOC. Others said that knowing how to predict the weather is just plain useful. And everyone found the class eye-opening. “It was surprising to me just how difficult it can be to predict tomorrow's weather, even when using the newest technology,” says Oren Katzen ’16. “I will be certain to be more forgiving to the weatherman in the future.”

By Michael Davidson

It is quite a challenge to pin down an electricity system that has grown 10.8 percent annually over the last decade, doubled power generation in just 7 years and added 80-90 gigawatts (GW) – the equivalent of the United Kingdom’s entire generating capacity –every year.

Nevertheless, some preliminary year-end statistics recently published by central agencies (NEA, NBS,CNREC) offer an interesting, though imperfect, snapshot of China’s power sector in 2013.

Notably, after a lull in 2012, electricity demand growth recovered last year owing to resurgent industrial demand. Coal retained its share in terms of capacity factor, while wind saw a rise in capacity factors indicating that some measures to improvement integration have had an impact. The “Big Five” state-owned generating companies – which collectively own 47 percent of Chinese generating capacity – made record profits in 2013, and the top electricity regulator was rolled into the top energy policy body in an attempt to streamline oversight.

Let’s take a spin through the 1,250 GW Chinese electricity system…

Electricity demand rebounds with heavy industry-led growth

In 2012, electricity demand growth fell to 5.6 percent, its lowest rate since 1998. In contrast, 2013 saw electricity growth regain 1.6 percentage points, to 7.2 percent growth for the year. While GDP grew at the same 7.7-7.8 percent rate in both years, last year’s surge in electricity demand was driven by anuptick in heavy industry-led growth. Crude steel production grew 7.5 percent compared to 3.1 percent in 2012, while the automobile production sector grew 18.4 percent, almost three times faster than in 2012. As over 70 percent of electricity production in China goes to satisfy industry demands, this readjustment drove national power sector demand (see figure, throughout, historic data is from the CEC– China Electricity Council.) More...

Alli Gold Roberts
MIT Joint Program on the Science and Policy of Global Change

Black carbon is one of the most potent air pollutants that contributes to global climate change, and is produced by the incomplete combustion of fossil fuels and forest fires. While scientists have known about the role of black carbon for decades, there’s been limited research to calculate global emissions. Now, MIT and National University of Singapore (NUS) researchers have developed a new method to calculate global black carbon emissions.

In a study published in last week’s Journal of Geophysical Research, the researchers calculated the global total of black carbon emissions at 17 teragrams a year between 2000 and 2005.  This result is significantly larger than the majority of global air pollution modeling studies, which employ a bottom-up approach. One such study found humans emitted only 7.5 teragrams of black carbon per year during the same five-year period—less than half the new estimate.

“Our results are the first to produce a global top-down estimation of the emissions of black carbon,” says Chien Wang, a senior research scientist with the Joint Program on the Science and Policy of Global Change and co-author of the study.

The top-down method used by Wang and his co-author Dr. Jason Cohen of NUS relies on gathering data from air measurement stations and satellites to sufficiently cover every region of the globe. In this study, data was collected from 238 different stations. They then compiled this data and used inverse modeling to determine the emissions from each of the major pollution regions.

“Current emissions inventories are mainly obtained by adding up estimates of emissions from ever sector of the economy and the environment to obtain a global estimate. This method creates uncertainty in the projections,” says Wang. “Our method eliminates some of these uncertainties by more accurately factoring in population and economic changes around the globe.”

The differences in the emissions estimates are most apparent in China and Southeast Asia. Wang predicts this is the result of the bottom-up method not capturing the rapid socioeconomic growth that has occurred in this region over the past 15 years.

Black carbon enters the atmosphere as small particles and warms the planet by absorbing heat and reducing the ability of the Earth to reflect light back out to space.

Because black carbon plays a key role in air pollution and global climate change, it is essential for policymakers to have an accurate picture of the severity of the problem.

“This top-down method isn’t perfect and still creates some unknowns in the estimates produced,” Wang says, but he suggests that combining both approaches would potentially improve estimates and further eliminate uncertainty. “We hope this work will open the door to further efforts to better quantify and reduce uncertainty in black carbon emissions estimates.”

More: Reprint 2014-1

The Global Young Academy (GYA) is an international group of two hundred young (up to ten years post PhD) scientists selected based on research excellence and commitment to impact. Through GYA, members are linked to the senior international academy network IAP, meet outstanding leaders of the international science community and may be nominated to contribute to international policy statements and working groups. Appointments are for a period of four years.

Selin's research focuses on using atmospheric chemistry modeling to inform decision-­â€making strategies on air pollution, climate change and toxic substances including mercury and persistent organic pollutants. She has also published articles and book chapters on the interactions between science and policy in international environmental negotiations, in particular focusing on global efforts to regulate hazardous chemicals and persistent organic pollutants. 

Selin, who will be formally appointed at a GYA symposium on May 21st, says she is very much looking forward to leveraging her new appointment to expand the reach of her science-policy work and educational initiatives.