Category: Environmental Defense

By Ben Levitan

This blog was co-authored by Surbhi Sarang, EDF Legal Fellow.

Since taking the helm at the Environmental Protection Agency (EPA), Scott Pruitt has attempted to hide his activities from scrutiny by limiting the public’s access to information.

He has ended the decades-long, bipartisan practice of releasing the daily schedules of top agency leadership, removed EPA webpages, and announced harmful policies close in time with private meetings with lobbyists from affected industries.

EDF has been at the forefront of efforts to promote transparency and accountability at EPA. That’s why we just filed a lawsuit to compel EPA to comply with its legal duty to release public records under the Freedom of Information Act (FOIA).

Scott Pruitt’s record of secrecy and ethical conflicts

Scott Pruitt’s opaqueness and secrecy have sharply contrasted with basic principles of good government.

Under the Ethics in Government Act of 1978, the Office of Government Ethics issued regulations for executive branch employees:

To ensure that every citizen can have complete confidence in the integrity of the Federal Government.

Among other requirements:

Employees shall act impartially and not give preferential treatment to any private organization or individual” and “shall endeavor to avoid any actions creating the appearance that they are violating the law or . . . ethical standards.

The Office of Government Ethics titled this regulation the “basic obligation of public service.”

Pruitt and his senior leadership have raised serious questions as to whether they are abiding by these principles.

In just one example, earlier this summer thirteen state Attorneys General formally objected to a guidance letter in which Pruitt expressed his flawed, misleading opinion about a crucial issue in litigation over the Clean Power Plan — America’s only nationwide limits on carbon pollution from existing power plants.

The Attorneys General wrote that Pruitt’s conduct was “inconsistent with his agreement not to participate in the litigation,” given that he repeatedly sued EPA over the Clean Power Plan when he served as Attorney General of Oklahoma.

Pruitt also discontinued the practice of releasing his schedule, along with the schedules of senior leadership.

The bipartisan practice of releasing schedules stretches back decades and was initiated expressly:

In order to make the public fully aware of [the Administrator’s] contacts with interested persons.

Following months of public pressure and more than 60 FOIA requests, Pruitt finally released a partial public account of his schedule. But that account provides only a minimal level of detail of how and with whom Pruitt spends his time.

Pruitt later released a more detailed appointments calendar, but it covered a limited date range and included many redactions worthy of additional scrutiny. And neither of those releases provides any transparency for other EPA senior officials.

To obtain any more information about how EPA leadership spends its time, EDF’s only recourse has been to demand the release of these public records under FOIA.

EDF’s efforts to promote transparency and accountability

EDF is taking action to protect important standards of transparency and accountability at EPA — and to keep the public informed about policymaking that directly impacts the health and environment of all Americans.

Our lawsuit concerns three FOIA requests that directly address the integrity of EPA’s operations. For each request, EPA’s legally mandated deadline for providing a response is several months overdue, despite EDF’s extensive outreach to EPA over many months in an effort to elicit the requested records.

The first request seeks records related to the ethics agreement that Pruitt signed shortly after his nomination to lead EPA, in which he outlined:

[S]teps that [he] will take to avoid any actual or apparent conflict of interest.

We submitted this FOIA request in January 2017 – more than nine months ago.

Pruitt’s ethics agreement diverged from the standard language used by the Office of Government Ethics – even though Pruitt’s longstanding and very public opposition to a litany of EPA’s public health and environmental safeguards calls into question his ability to be impartial, particularly on matters in which he represented Oklahoma and long ago took fixed positions. Since taking the oath of office as Administrator, Pruitt has actively tried to undermine public health and environmental protections — like the Clean Power Plan — and has proposed to repeal protections that he had long attacked while Attorney General of Oklahoma.

Our FOIA request seeks records pertaining to the evaluation of Pruitt’s actual or potential conflicts of interest, including any analysis that informed his ethics agreement.

The second request is for records related to Pruitt’s and his senior managers’ schedules.

The most complete information we’ve received so far on Pruitt’s activities is only a select snapshot released through a FOIA request. That snapshot contains more than 100 redacted calendar appointments, and only runs through mid-May.

Even this limited information reveals the special access granted to polluter lobbyists — many of whom come from industries that have supported Pruitt’s political career for years. A more comprehensive release, including the calendars of senior EPA managers, would provide a fuller picture of the constituency that Pruitt and his political staff are serving.

The third request is for public documents related to threats to scientific integrity at EPA.

EDF requested these records in light of the Trump Transition Team’s efforts to single out civil servants at the Department of Energy who worked on climate science and policy. Since we submitted this FOIA request more than seven months ago, subsequent events — including the removal of EPA’s Climate Science website, scientific distortions that accompanied the proposal to repeal the Clean Power Plan, threatened efforts that would compromise the integrity of EPA advisory boards, and the muzzling of EPA scientists who were scheduled to deliver public presentations on climate change — have only increased the urgency of providing public access to records about the treatment of scientific integrity at EPA.

EDF will continue working to protect transparency and accountability at EPA by supporting Americans’ ability to access information about health and environmental policies, and by shining a light on the Trump Administration’s attacks on vital safeguards for families and communities across America.

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By Ryan O’Connell
Climate change poses clear threats to the environment and global ecosystems, but it also presents risks to human health. Evidence suggests that droughts, heat waves, and extreme weather events will become more severe as our planet con…

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By Kate Zerrenner

It’s time to rely on water-smart power

Energy Secretary Rick Perry is trying to prop up coal and nuclear companies under the guise of enhanced “resiliency.” The Department of Energy’s (DOE) proposal does not define resiliency, nor does it even make clear what resiliency means in the context of the electric grid.

Resiliency in the energy sector generally, however, depends on water. The majority of the electricity that powers our world runs on century-old technology, guzzling down our most precious resource: water. Depending on the type of technology, generating just one megawatt-hour of electricity could use anywhere from 500 to 50,000 gallons. Solar and wind, on the other hand, use negligible amounts of water, and energy efficiency uses none.

Yet neither the DOE’s proposal nor its recent study on grid reliability touches on climate and water. Specifically, there is no mention of how climate change affects water availability or what that means for electric reliability. If Secretary Perry is really concerned about resiliency, water should be a key focus. And as a former governor from a drought-stricken state, he should know better.

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If we don’t talk about water, are we really talking about resiliency?
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Thirsty energy and a changing climate

Eighty-five percent of U.S. electricity is generated by incredibly thirsty resources: fossil fuel and nuclear power plants. As a result, the country’s power sector withdraws more water than any other sector of the economy. In 2010 (the most recent data year), the power sector withdrew 161 billion gallons of water per day, accounting for about half of all freshwater withdrawals in the country (“withdrawal” is the amount of water taken from the water source, whereas consumption is the portion of that water used and not returned to the original source for reuse).

That’s why if we’re talking about reliability, water availability has to be part of the conversation.

Secretary Perry, of all people, should understand this. He was the Governor of Texas for 14 years, during which time the state suffered through one of the worst droughts in its history. The Electric Reliability Council of Texas (ERCOT), which manages the electricity of nearly 90 percent of the state, frequently ran into reliability issues related to heat and drought during the driest years. Curtailment – or restricting power – and brownouts were regular topics of conversation.

Why? When it’s hot and dry, people turn their air conditioners up, which increases overall electric demand. When demand increases, more power is needed, tapping into more and more of the decreasing supplies of water. It’s a vicious cycle, and water is at the heart of it.

Add in climate predictions, and we’re looking at hotter and drier as the new norm for much of the country. The effects won’t just be in places like Texas and the West – recently, New England and the Southeast suffered unprecedented droughts.

Although most places have been able to avoid power shutdowns so far, recent years have seen curtailment and stress, especially on nuclear power (the second thirstiest energy source after coal) in Illinois, Georgia, and South Carolina.

Demanding a water-conscious future

To meet future energy demands and ensure reliable electricity, low-carbon and water-smart energy choices need to be at the forefront of electricity decision-making. Renewable energy is a win-win solution to water scarcity on a warming planet, and a future focused on renewables will cut carbon pollution, while easing the stress climate change puts on water availability.

If the Department of Energy wants resiliency, Secretary Perry should prioritize innovation and research and development – not seek to prop up the thirsty coal and nuclear industries.

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By Ronny Sandoval

After a record-breaking hurricane season and catastrophic wildfires in California, the vulnerabilities of our electric system – and the urgent need to upgrade it – have never been clearer.

It took more than 10 days of around-the-clock work to restore electricity to 350,000 customers after fires struck California wine country last month. Returning service to all 4.4 million power customers in Florida after Hurricane Irmatook almost as long – and 70 percent of Puerto Ricans still lack power six weeks after Hurricane Maria.

Such crippling outages contribute to $250 billion in economic losses globally every year.

But there are solutions available on the market today that can reduce the impact of these outages. By investing in technologies that modernize our electric grid, and with careful planning, we can also create a cleaner and more efficient electricity system overall.

Here are three cost-effective investments in this “modern grid” that could keep the lights on for more people during future storms.

1. Distributed energy systems improve resiliency

A modern grid makes how we make, move, and use electricity easier, more efficient, and cleaner.

Microgrids, for example, can go a long way to improve the resiliency of our electric system. These specialized energy systems can serve a defined area, regardless of whether the main power grid is active, through the use of batteries and localized generation such as solar, wind and other renewable sources.

We saw the value of microgrids first-hand after Hurricane Sandy five years ago. During that disaster, microgrid systems kept the power flowing in spots stretching from Maryland to Manhattan – including at Princeton University’s sprawling campus in New Jersey when much of the Garden State was blacked out.

Today, there are about 160 microgrids operating in the United States, and the capacity of such systems is expected to double between 2016 and 2020.

These systems can be complex, however, and some of the rules governing the energy provided by such sites have yet to catch up with advances in technology or society’s need. It explains why they have not been adopted at the scale required to meet our demand for resiliency.

More can be done at the state and local level to revise these outdated rules and provide education and technical support to customers and facilities that could most benefit from microgrids.

2. New technologies detect outages faster

The electric system has been around for a very long time, but has yet to fully harness many of the same digital tools that have modernized internet-based communications.

Sensors, controls and other advanced technologies can be used to remotely detect and manage outages with better accuracy and results. What’s more, many of these same solutions can reduce energy waste by making the delivery of electricity to homes and businesses more efficient.

After a few initial pilots in 2013, Duke Energy expanded some of these energy saving applications to cover nearly all of its electrical circuits in Ohio. The utility has reliably reduced its voltage levels by 2 percent, cutting waste and saving customers money while reducing pollution.

We think more utilities could stand to gain from such tools.

3. A redesigned and measured grid is stronger

To build a more resilient grid, utilities must work together with their customers to identify conditions that make their systems vulnerable and to develop practicable solutions.

Together with local leaders, consumer advocates, environmental groups and other stakeholders, a system can be designed to meet the area’s unique needs and to quickly bounce back after disruptions.

That can mean burying power lines underground and reaching an agreement with power customers and regulators on how to pay for the associated capital costs – or replacing wooden poles with steel or other materials where burying lines isn’t the right solution.

But utilities must also measure their own success. Without knowing how grid upgrades have prevented or limited outages, they’ll have difficulty knowing which investments have the biggest impact.

Our society’s reliance on electricity has grown over the last several decades, but so have the sources of potential outages. A more robust planning process and upgrades that fully account for these changing system conditions will help us establish the sustainable and resilient electric system we need.

Photo source: Flickr/Oran Viriyincy

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By Ellen Shenette

This year, the Atlantic basin had eight consecutive storms develop—the first time in 124 years. The storms—and by storms I mean big storms—have had catastrophic effects on families, communities and the economy at large. Millions of people were left powerless, access to clean drinking water was compromised and homes were destroyed. It will take decades for the country to recover from this devastation, and hurricane season is only halfway over.

And as the intensity of these storms increases, so do their price tags. Together, hurricanes Harvey, Irma and Maria, which hit the U.S. earlier this fall, are estimated to cost $150-$200 billion in combined destruction. This is an enormous blow to the economy and to tax payers’ wallets.

To those of us on the east coast, this sounds awfully similar to destruction caused by Hurricane Sandy, which hit New York City and New Jersey hard this time five years ago. That’s why it’s important to ask: could the devastation have been avoided, or at least reduced?

Cities are building back, stronger

This year’s storms showed the vulnerability of centralized electric grids, and the need for a modernized system. When Hurricane Maria hit Puerto Rico, 100 percent of the territory’s power supply was cut off to its 1.57 million customers and 80 percent of the transmission and distribution system destroyed. The rebuilding and repairs will go on for months.

Fortunately, changes to our current electrical system can prevent some of this. Microgrids–localized power grids that can operate independently from the main, centralized grid–are designed to provide power when the traditional grid is not functional. The ability to act autonomously strengthens the power system’s reliability and resilience, and protects critical infrastructure, such as hospitals, water treatment facilities and police stations in event of an extreme weather event like we saw this year.

They can also be “clean” by adding renewables like solar and wind that reduce reliance on fossil fuels and diesel generators—which may be compromised in a major storm event. And, since microgrids are not transmitting electricity over long distances, they don’t require an extensive network of transmission lines, allowing them to get up and running soon after a storm hits.

In the aftermath of Hurricane Sandy, the City of Hoboken announced it would use recovery funds to design a microgrid that would increase its sustainability and resiliency. With the help of EDF Climate Corps, the city of Hoboken created a Microgrids Toolkit. The toolkit includes a centralized dashboard for monitoring energy use, a timeline for implementation and scorecard for tallying up the potential benefits. It’s a customizable tool that can be used to scale projects across cities, creating a more resilient coastline.

The toolkit is currently being used to study the potential for additional microgrids in other municipalities across the state.

Spotlight: NYC taking action

Now New York is jumping on the microgrid train. During Sandy, nearly 2 million customers lost power and $19 billion in damages incurred. Some of the most important utility infrastructure on the city’s waterfront was destroyed, shedding light on the city’s large vulnerability issue. The New York Governor’s Office of Storm Recovery, in charge of coordinating statewide recovery efforts for Superstorm Sandy and other major weather events, has vowed to not only build back, but build back stronger.

The agency, in coordination with NYSERDA, is working on a community Microgrids Program that would mitigate future instances of power outages. EDF Climate Corps fellow Ben Bovarnick was hired to develop up to five microgrids in municipalities to demonstrate the feasibility and best practices for publicly-financed projects. The program had started to identify optimal projects, but sought new ideas for integrating advanced energy technologies and renewable energy into the projects.

Bovarnick identified opportunities for energy storage to reduce electricity demand and provide cost savings as well as improved system stability. Battery storage will also help with peak shaving and back up electricity, which has the potential to improve the project value and save the municipality on annual electricity expenditures.

Prepare, not react

The truth is, these superstorms are likely to continue, and their severity may increase. That means preparedness is key. States and municipalities, especially on the coast, must work together to create a comprehensive framework to tackle resiliency. Our efforts and finances should be invested in developing solutions that prevent extreme devastation, as opposed to cleaning up the aftermath.

Sandy was our wakeup call. But although post-Sandy protection-projects were introduced, there’s still a long way to go. Fortunately, the technology is out there to make resiliency a reality.

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Follow Ellen on Twitter, @ellenshenette

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By Tom Neltner

Tom Neltner, J.D., is Chemicals Policy Director and Maricel Maffini, Ph.D., Consultant

For more than 40 years, the Food and Drug Administration (FDA) has conducted the Total Diet Study (TDS) to monitor levels of approximately 800 pesticides, metals, and other contaminants, as well as nutrients in food. The TDS’s purposes are to “track trends in the average American diet and inform the development of interventions to reduce or minimize risks, when needed.” By combining levels of chemicals in food with food consumption surveys, the TDS data serve a critical role in estimating consumers’ exposure to chemicals.

From 2004 to 2012 (except for 2007), FDA collects and tests about 280 food types for perchlorate, a chemical known to disrupt thyroid hormone production. This information is very important, because for the many pregnant women and children with low iodine intake, even transient exposure to high levels of perchlorate can impair brain development.

The agency published updates on food contamination and consumers’ exposure to perchlorate in 2008 (covering years 2004-2006) and in 2016 (covering 2008-2012). On its Perchlorate Questions and Answers webpage, FDA says it found “no overall change in perchlorate levels across foods” in samples collected between 2008 and 2012 compared to those collected between 2005 and 2006. It also notes that there were higher average levels in some food and lower in others between the time periods and suggests that a larger sampling size or variances in the region or season when the samples were collected may account for the differences.

FDA’s Q&A webpage masks the most disturbing part of the story

FDA’s attempt at providing consumers with information about the presence of a toxic chemical in food and what it means for their health falls short. By focusing on the similar average level of perchlorate across foods, FDA masks the disturbing fact that children are consuming increasing amounts of perchlorate: 35% for infants, 23% for toddlers and 12% for children between 2 and 6 from 2004-2006 to 2008-2012. The agency’s webpage notes the exposures in 2008-2012 but fails to mention the increase reported by its own scientists.

FDA’s webpage also fails to mention that the perchlorate Reference Dose (RfD), the amount of exposure unlikely to result in an adverse health effect, was set more than a decade ago and does not reflect the latest research. In 2013, the Environmental Protection Agency (EPA)’s Science Advisory Board indicated that the RfD may not sufficiently protect pregnant women and young children. As a result, EPA, with FDA’s support, is in the final stages of updating that number. FDA’s estimated average exposures to perchlorate by infants and toddlers was very close to the RfD, and many children may well exceed the outdated RfD.

FDA failed to investigate extraordinarily high levels of perchlorate

In the 2016 update, we noticed that some foods, such as bologna, salami and rice cereal, had very high levels, far greater than in 2004-2006. In May 2017, FDA provided more data that enabled us to learn what region and year the samples were collected.

We knew from FDA’s Compliance Program Guidance Manual that staff are asked to follow-up on any unusual analytical findings in the TDS samples (Figure 1). So in June 2017, we filed a Freedom of Information Act (FOIA) request seeking details for 47 composite samples (18 baby foods and 29 other foods) that, in our view, had unusually high levels of perchlorate. We asked for any information regarding:

• Test results for composite and individual samples (Figure 2);
• Product details on the individual foods; and
• Any follow-up testing or investigations.

FDA’s response to the FOIA raises concerns. First, the agency did not have criteria for following up on perchlorate. Specifically, staff requested guidance “on cut-off value of perchlorate in the composite that would trigger analysis of individual foods,” but we didn’t find any in the documents provided to us. Without this guidance, some staff listed composite samples with at least 20 ppb as “noteworthy;” others used 15 ppb as the trigger for re-testing and confirmation. All 47 samples we asked FDA about were above these levels. Yet, there was no retesting of the composite for 27 of them.

Second, staff confirmed the results for 20 composite samples which should have triggered tests on the three individual samples that made up the composite.

But FDA only provided information for four individual foods:

• Baby food rice cereal (173 ppb in composite in summer of 2008): Newark sample had 252 ppb; New York City had 112 ppb; and Philadelphia had 3 ppb.
• Baby food carrots (74 ppb in composite in winter of 2011): Denver sample had 163 ppb; Los Angeles sample had 111 ppb; and Seattle sample had 0 ppb.
• Baby food barley cereal (67 ppb in composite in spring of 2008): Dallas had 182 ppb; and Tampa and Baltimore had 1 ppb.
• Baby food oatmeal with fruit (42 ppb in composite in summer of 2008): New York City had 82 ppb; Newark had 3 ppb; and Philadelphia had 0 ppb.

Even more disturbing is that, despite confirming the results in the composite samples, FDA could find no records that the individual samples in the highest levels, bologna with 1557 ppb, 1,090 and 686 ppb for collard greens and 686 ppb for salami lunchmeat, were ever tested.

Similarly, the agency could not find any records of the TDS coordinator investigating the possible cause of the high levels of contamination or any communication between the coordinator and others in the Center for Food Science and Applied Nutrition that oversees the TDS. Also not available were the receipts essential to identifying the brand and lot of the samples with unusual high levels of perchlorate; therefore EDF was unable to follow-up.

Conclusion

The agency’s apparent lack of follow-up when faced with jaw-dropping levels of a toxic chemical in food is disturbing. While testing the products is a critical first step, FDA needs to investigate the reasons for the high levels so that it can protect the food supply. Identifying the cause and crafting interventions to reduce or minimize risks, as stated in the TDS purpose statement, is especially important for toxics like perchlorate, where even short exposures during critical life stages may cause lasting harm to a child’s developing brain. But for this to happen, FDA needs to acknowledge the evidence on sources of perchlorate in food, such as its use in packaging or from degraded bleach, and clearly explain what the implications are for the health of children and pregnant women, especially those with low iodine intake.

Update on related perchlorate issue: FDA has not yet responded to EDF’s and eight other public interest organizations’ objection to the agency’s May 4, 2017 decision to reject a petition to ban perchlorate from uses in contact with food. The objection and request for evidentiary hearing were filed on June 4, 2017.

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By Casey Ivanovich

(This post was co-authored by EDF Climate Scientist Ilissa Ocko)

Imagine cutting down a tree. Initially, you chop and chop … but not much seems to change. Then suddenly, one stroke of the hatchet frees the trunk from its base and the once distant leaves come crashing down.

It’s an apt metaphor for one of the most alarming aspects of climate change – the existence of “tipping elements.”

These elements are components of the climate that may pass a critical threshold, or “tipping point,” after which a tiny change can completely alter the state of the system. Moving past tipping points may incite catastrophes ranging from widespread drought to overwhelming sea level rise.

Which elements’ critical thresholds should we worry about passing thanks to human-induced climate change?

You can see the answer on this graphic – and find more information below.

The most immediate and most worrisome threats

• Disappearance of Arctic Summer Sea Ice – As the Arctic warms, sea ice melts and exposes dark ocean waters that reflect sunlight much less efficiently. This decreased reflectivity causes a reinforcement of Arctic warming, meaning that the transition to a sea-ice free state can occur on the rapid scale of a few decades. Some scientists have suggested that we have already passed this tipping point, predicting that Arctic summers will be ice-free before mid-century.
• Melting of the Greenland Ice Sheet – The Arctic warming feedback described above may one day render Greenland ice-free. Research predicts that the tipping point for complete melt can occur at a global temperature rise of less than two degrees Celsius – a threshold that may be surpassed by the end of this century. While the full transition to an ice-free Greenland will take at least a few hundred years, its impacts include global sea level rise of up to 20 feet.
• Disintegration of the West Antarctic Ice Sheet – The bottom of this ice sheet lies beneath sea level, allowing warming ocean waters to slowly eat away at the ice. There is evidence that this tipping point has already been surpassed – possibly as early as 2014. Like the Greenland Ice Sheet, full collapse would require multiple centuries, but it could result in sea level rise of up to 16 feet.
• Collapse of Coral Reefs – Healthy corals maintain a symbiotic relationship with the algae that provide their primary food source. As oceans warm and become more acidic, these algae are expelled from the corals in an often fatal process called coral bleaching. Research predicts that most of our remaining coral systems will collapse even before a global temperature rise of two degrees Celsius.

Tipping points in the distant future

• Disruption of Ocean Circulation Patterns – The Thermohaline Circulation is driven by heavy saltwater sinking in the North Atlantic, but this water is becoming fresher and lighter as glaciers melt in a warming climate. The change in water density may prevent sinking and result in a permanent shutdown of the circulation. Research suggests that weakening of the Thermohaline Circulation is already in progress, but that an abrupt shutdown is unlikely to occur in this century. Some models suggest that these changes may prompt a secondary tipping element in which the subpolar gyre currently located in the Labrador Sea shuts off. Such a change would dramatically increase sea level, especially on the eastern coast of the United States.
• Release of Marine Methane Hydrates – Large reservoirs of methane located on the ocean floor are stable thanks to their current high pressure-low temperature environment. Warming ocean temperatures threaten the stability of these greenhouse gas reservoirs, but the necessary heat transfer would require at least a thousand years to reach sufficient depth, and may be further delayed by developing sea level rise.
• Ocean Anoxia – If enough phosphorous is released into the oceans – from sources including fertilizers and warming-induced weathering, or the breakdown of rocks –regions of the ocean could become depleted in oxygen. However, this process could require thousands of years to develop.

Potentially disastrous elements, but with considerable uncertainty

• Dieback of the Amazon Rainforest – Deforestation, lengthening of the dry season, and increased summer temperatures each place stress on rainfall in the Amazon. Should predictions that at least half of the Amazon Rainforest convert to savannah and grasslands materialize, a considerable loss in biodiversity could result. However, the dieback of the Amazon Rainforest ultimately depends on regional land-use management, and on how El Niño will influence future precipitation patterns.
• Dieback of Boreal Forests – Increased water and heat stress could also lead to a decrease in boreal forest cover by up to half of its current size. Dieback of boreal forests would involve a gradual conversion to open woodlands or grasslands, but complex interactions between tree physiology, permafrost melt, and forest fires renders the likelihood of dieback uncertain.
• Weakening of the Marine Carbon Pump – One mechanism through which oceanic carbon sequestration takes place is the marine carbon pump, which describes organisms’ consumption of carbon dioxide through biological processes such as photosynthesis or shell building. As ocean temperatures rise, acidification progresses, and oxygen continues to be depleted, these natural systems could be threatened and render the carbon sequestration process less efficient. More research is necessary in order to quantify the timescale and magnitude of these effects.

Tipping elements complicated by competing factors

• Greening of the Sahara/Sahel – As sea surface temperatures rise in the Northern Hemisphere, rainfall is projected to increase over the Sahara and Sahel. This increased rainfall would serve to expand grassland cover in the region, but is balanced by the cooling effect of human-emitted aerosols in the atmosphere.
• Chaotic Indian Summer Monsoon – The fate of the Indian Summer Monsoon similarly depends upon a balance of greenhouse gas warming and aerosol cooling, which strengthen and weaken the monsoon, respectively. On the timescale of a year, there is potential for the monsoon to adopt dramatic active and weak phases, the latter resulting in extensive drought.

More research necessary to establish as tipping elements

• Collapse of Deep Antarctic Ocean Circulation – As in the case of the Thermohaline Circulation, freshening of surface waters in the Southern Ocean due to ice melt may slowly alter deep water convection patterns. However, the gradual warming of the deep ocean encourages this convection to continue.
• Appearance of Arctic Ozone Hole – Unique clouds that form only in extremely cold conditions currently hover over Antarctica, serving as a surface for certain chemical reactions and facilitating the existence of the ozone hole. As climate change continues to cool the stratosphere, these “ice clouds” could begin formation in the Arctic and allow the development of an Arctic ozone hole within a year.
• Aridification of Southwest North America – As global temperatures rise, consequential changes in humidity prompt the expansion of subtropical dry zones and reductions in regional runoff. Models predict that Southwest North America will be particularly affected, as moisture shifts away from the southwest and into the upper Great Plains.
• Slowdown of the Jet Stream – A narrow and fast moving air current called a jet stream flows across the mid-latitudes of the northern hemisphere. This current separates cold Arctic air from the warmer air of the south and consequentially influences weather in its formation of high and low pressure systems. A slowing of the jet stream has been observed over recent years. Should slowing intensify, weather patterns could persist over several weeks with the potential to develop into extended extreme weather conditions.
• Melting of the Himalayan Glaciers – Several warming feedbacks render the Himalayan glaciers vulnerable to dramatic melt within this century, though limitations on data availability complicate further study. Dust accumulation on the mountainous glaciers and the continual melt of snow and ice within the region both prompt a decrease in sunlight reflectivity and amplify regional warming.

Gradual, continuous changes

• More Permanent El Nino State – 90 percent of the extra heat trapped on Earth’s surface by greenhouse gases is absorbed by the oceans. Though still under debate, the most likely consequence of this oceanic heat uptake is a gradual transition to more intense and permanent El Nino/Southern Oscillation (ENSO) conditions, with implications including extensive drought throughout Southeast Asia and beyond.
• Permafrost Melting – As global temperatures rise and the high latitudes experience amplified warming, melting permafrost gradually releases carbon dioxide and methane into the atmosphere and creates a feedback for even more warming.
• Tundra Transition to Boreal Forest – Much like the conversion of the Amazon Rainforest and boreal forests to other biomes, tundra environments may transition into forests as temperatures increase. However, this process is more long-term and continuous.

With a range of critical thresholds on the horizon, each tipping element demonstrates the potential implications of allowing climate change to progress unchecked.

As tipping points loom ever closer, the urgency for emissions mitigation escalates in hopes of sustaining the Earth as we know it.

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