Human-caused climate change is disrupting ecosystems and people’s lives around the world. It is melting glaciers, increasing wildfires, and shifting vegetation across vast landscapes. These impacts have reached national parks around the world and in the United States. Until now, however, no analysis had examined climate change trends across all 417 U.S. national parks.
The United States established the first national park in the world, Yellowstone National Park, in 1872. U.S. national parks today protect some of the most irreplaceable natural areas and cultural sites in the world. Colleagues and I aimed to uncover the magnitude of human-caused climate change on these special places. We conducted the first spatial analysis of historical and projected temperature and precipitation trends across all U.S. national parks and compared them with national trends.
Our newly published results reveal that climate change has exposed the national parks to conditions hotter and drier than the country as a whole. This occurs because extensive parts of the parks are in extreme environments – the Arctic, high mountains, and the arid southwestern United States.
Rapid warming and drying
National parks conserve the most intact natural places in the country. They harbor endangered plants and animals and unique ecosystems. They also help assure human well-being by protecting watersheds that provide drinking water to people and by storing carbon, which naturally reduces climate change.
Our findings show that temperatures in the national park area increased at double the national rate from 1895 to 2010. At the same time, precipitation decreased across a greater fraction of the national park area than across the United States as a whole.
Our analysis of climate trends starting in 1895 showed that temperatures increased most in Denali National Preserve, Alaska, and rainfall declined most in Honouliuli National Monument, Hawaii. Hotter temperatures from human-caused climate change have intensified droughts caused by low precipitation in California and the southwestern United States.
Human-caused climate change has caused historical impacts in places where we found significant past temperature increases. These impacts include melting of glaciers in Glacier Bay National Park, Alaska, tree death from bark beetles in Yellowstone National Park, upslope vegetation shifts in Yosemite National Park, California, and northward vegetation shifts in Noatak National Preserve, Alaska.
To quantify potential future changes, we analyzed all available climate model projections from the Intergovernmental Panel on Climate Change. Continued greenhouse gas emissions under the highest emissions scenario could increase U.S. temperatures in the 21st century six times faster than occurred in the 20th century.
This could increase temperatures in national parks up to 9 degrees Celsius by 2100, with the most extreme increases in Alaska, and reduce precipitation by as much as 28 percent, in the national parks of the U.S. Virgin Islands. Heating could outpace the ability of many plant and animal species to move and stay in suitable climate spaces.
In places where models project high temperature increases, research has found high vulnerabilities of ecosystems. These vulnerabilities include severely increased wildfire in Yellowstone National Park, extensive death of Joshua trees in Joshua Tree National Park, California, and possible disappearance of American pika, a small alpine mammal, from Lassen Volcanic National Park, California.
Our research provides climate data to analyze vulnerabilities of plants, animals and ecosystems. The data can also help park managers develop adaptation measures for fire management, invasive species control and other ways to protect parks in the future.
For example, based on analyses of the vulnerability of ecosystems to increased wildfire under climate change, parks can target prescribed burning and wildland fire in the short term to reduce the unnatural buildup of fuels that can cause catastrophic wildfires in the long term.
Reducing emissions can help parks
Ultimately, our results indicate that reducing greenhouse gas emissions from cars, power plants and other human sources can save parks from the most extreme heat. Compared to the highest emissions scenario, reduced emissions would lower the rate of temperature increase in the national parks by one-half to two-thirds by 2100.
Cutting greenhouse gas emissions through energy conservation, improved efficiency, renewable energy, public transit and other actions would reduce the magnitude of human-caused climate change, helping save the U.S. national parks for future generations.
The Trump administration’s withdrawal from the Paris climate agreement was greeted with dismay around the world. Less well known, but probably just as damaging to emissions reductions, was freezing standards for carbon dioxide emissions from cars in July.
The erosion of US federal climate policy has made action from individual states far more important. As Australia grapples with yet another failure to implement a national emissions policy, what can we learn from America?
And is it time for Australian states to reach out directly to like-minded states in other parts of the world to tackle global climate issues?
Strong state action
From the outside, the US often looks like a bastion of climate change denial and very large cars, but a group of US states has nevertheless made some of the most dramatic progress in curbing emissions of any jurisdictions in the world.
Consider New Jersey. In 1998, while the Kyoto Protocol was being negotiated (and ultimately rejected by George W. Bush), Governor Christine Whitman ordered that the state pursue an emissions target of 3.5% below 1990 levels by 2005.
Since then, New Jersey has consistently adopted emissions reduction targets in line with global agreements, effectively bypassing the weaker standards at the federal level. Several other, mostly Democrat, states across the nation took similar action during the Bush administration, placing caps on emissions from power generation, establishing internal carbon trading systems, and adopting ambitious state emissions targets.
California’s regulation of air quality goes back even further. In response to Los Angeles’ smog problem – arising from a confluence of geographical conditions, warm weather, and high automobile use – Sacramento introduced smog restrictions on automobiles in 1960. This predated both the establishment of the US Environmental Protection Agency and any meaningful federal effort to regulate air quality or car pollution. In 1970, when President Nixon established the EPA and Congress gave teeth to the Clean Air Act, California was granted special waivers to adopt stricter anti-smog measures. The state has done so ever since.
Under Governor Arnold Schwarzenegger, and as part of a much broader climate change initiative, reduction targets for CO₂ emissions from automobiles were added to the existing anti-smog rules. By this time, a number of states were also following California’s more stringent standards. These included states bordering California where auto dealers wished to sell California-compliant cars, but also East Coast progressive states pursuing ambitious climate change plans of their own.
Australia is not in exactly the same position as the the US – for example, we are virtually unique in the developed world for having no fuel efficiency standards for cars – but there are some striking similarities.
The policy deadlock at the federal level has made action from states, and even local councils, vitally important.
At the same time as the federal government is struggling to put emissions reduction on the national agenda, Victoria has made a huge commitment to rooftop solar. South Australia, which leads the country in renewable energy generation, is now a net energy exporter for the first time.
While the Queensland state government grapples over the Adani coal mine, a May report found that billions of dollars in renewable energy projects are underway.
The Trump effect
The Trump administration is widely expected to repeal many Obama-era limits on pollution. Auto emissions standards came onto the chopping-block in July, when the administration unveiled its plan to “Make Cars Great Again” by freezing fuel efficiency standards at 37 miles per gallon.
The EPA has also announced that it will revoke California’s waiver to set more stringent standards, which 13 other states including New York now also follow.
In both cases, the Trump administration is seeking not just to relax federal climate standards, but to prevent states from setting more stringent policies should they wish to. And in both cases, these matters will be settled by the courts.
California announced it would lead a legal challenge to protect the waiver on the same day as the administration announced it would revoke it. When the EPA moves to repeal the Clean Power Plan, the same set of states will likely sue to protect it.
Why this matters globally
These legal fights have global ramifications. The 13 states that follow California’s waiver have a population of 130 million. These states have pledged, through auto emissions standards and clean energy targets, to meet the Paris Climate goals – using their own policy autonomy to circumvent Trump’s withdrawal.
These states have also pledged to pursue independent diplomacy with other national and sub-national jurisdictions around the world, sharing best practise and pursuing climate cooperation.
The EPA has so far lost a number of legal challenges, and is by no means guaranteed to win its case against California. Should these states prevail, Australia has an opportunity to pursue meaningful climate diplomacy directly with the American states.
A 130 million-person market for sustainable technologies also presents a substantial opportunity for Australian businesses in the renewables sector.
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American states have a framework in place for international partnerships on climate. State governors and city mayors across the country are eager to brand themselves as international climate change leaders. As Australian federal politics grinds through another round of energy policy and climate change debate, it might be time for Australian states to look outside our borders for inspiration and co-operation.
Awareness is rising worldwide about the scourge of ocean plastic pollution, from Earth Day 2018 events to the cover of National Geographic magazine. But few people realize that similar concentrations of plastic pollution are accumulating in lakes and rivers. One recent study found microplastic particles – fragments measuring less then five millimeters – in globally sourced tap water and beer brewed with water from the Great Lakes.
According to recent estimates, over 8 million tons of plastic enter the oceans every year. Using that study’s calculations of how much plastic pollution per person enters the water in coastal regions, one of us (Matthew Hoffman) has estimated that around 10,000 tons of plastic enter the Great Lakes annually. Now we are analyzing where it accumulates and how it may affect aquatic life.
No garbage patches, but lots of scrap on beaches
Plastic enters the Great Lakes in many ways. People on the shore and on boats throw litter in the water. Microplastic pollution also comes from wastewater treatment plants, stormwater and agricultural runoff. Some plastic fibers become airborne – possibly from clothing or building materials weathering outdoors – and are probably deposited into the lakes directly from the air.
Sampling natural water bodies for plastic particles is time-consuming and can be done on only a small fraction of any given river or lake. To augment actual sampling, researchers can use computational models to map how plastic pollution will move once it enters the water. In the ocean, these models show how plastic accumulates in particular locations around the globe, including the Arctic.
When plastic pollution was initially found in the Great Lakes, many observers feared that it could accumulate in large floating garbage patches, like those created by ocean currents. However, when we used our computational models to predict how plastic pollution would move around in the surface waters of Lake Erie, we found that temporary accumulation regions formed but did not persist as they do in the ocean. In Lake Erie and the other Great Lakes, strong winds break up the accumulation regions.
Subsequent simulations have also found no evidence for a Great Lakes garbage patch. Initially this seems like good news. But we know that a lot of plastic is entering the lakes. If it is not accumulating at their centers, where is it?
Using our models, we created maps that predict the average surface distribution of Great Lakes plastic pollution. They show that most of it ends up closer to shore. This helps to explain why so much plastic is found on Great Lakes beaches: In 2017 alone, volunteers with the Alliance for the Great Lakes collected more than 16 tons of plastic at beach cleanups. If more plastic is ending up near shore, where more wildlife is located and where we obtain our drinking water, is that really a better outcome than a garbage patch?
Searching for missing plastic
We estimate that over four tons of microplastic are floating in Lake Erie. This figure is only a small fraction of the approximately 2,500 tons of plastic that we estimate enter the Lake each year. Similarly, researchers have found that their estimates of how much plastic is floating at the ocean’s surface account for only around 1 percent of estimated input. Plastic pollution has adverse effects on many organisms, and to predict which ecosystems and organisms are most affected, it is essential to understand where it is going.
We have begun using more advanced computer models to map the three-dimensional distribution of plastic pollution in the Great Lakes. Assuming that plastic simply moves with currents, we see that a large proportion of it is predicted to sink to lake bottoms. Mapping plastic pollution this way begins to shed light on exposure risks for different species, based on where in the lake they live.
According to our initial simulations, much of the plastic is expected to sink. This prediction is supported by sediment samples collected from the bottom of the Great Lakes, which can contain high concentrations of plastic.
In a real lake, plastic does not just move with the current. It also can float or sink, based on its size and density. As a particle floats and is “weathered” by sun and waves, breaks into smaller particles, and becomes colonized by bacteria and other microorganisms, its ability to sink will change.
Better understanding of the processes that affect plastic transport will enable us to generate more accurate models of how it moves through the water. In addition, we know little so far about how plastic is removed from the water as it lands on the bottom or the beach, or is ingested by organisms.
Prediction informs prevention
Developing a complete picture of how plastic pollution travels through waterways, and which habitats are most at risk, is crucial for conceiving and testing possible solutions. If we can accurately track different types of plastic pollution after they enter the water, we can focus on the types that end up in sensitive habitats and predict their ultimate fate.
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Of course, preventing plastic from entering our waterways in the first place is the best way to eliminate the problem. But by determining which plastics are more toxic and also more likely to come into contact with sensitive organisms, or end up in our water supply, we can target the “worst of the worst.” With this information, government agencies and conservation groups can develop specific community education programs, target cleanup efforts and work with industries to develop alternatives to products that contain these materials.
A global plastic waste crisis is building, with major implications for health and the environment. Under its so-called “National Sword” policy, China has sharply reduced imports of foreign scrap materials. As a result, piles of plastic waste are building up in ports and recycling facilities across the United States.
In response, support is growing nationally and worldwide for banning or restricting single-use consumer plastics, such as straws and grocery bags. These efforts are also spurred by chilling findings about how micro-plastics travel through oceans and waterways and up the food chain.
I have studied global trade in hazardous wastes for many years and am currently completing a book on the global politics of waste. In my view, today’s unprecedented level of public concern is an opportunity to innovate. There is growing interest in improving plastic recycling in the United States. This means getting consumers to clean and sort recyclables, investing in better technologies for sorting and reusing waste plastics, and creating incentives for producers to buy and use recycled plastic.
Critiques of recycling are not new, and critiques of recycling plastic are many, but I still believe it makes sense to expand, not abandon, the system. This will require large-scale investment and, in the long term, implementing upstream policies, including product bans.
Easy to use, hard to destroy
Plastics make products lighter, cheaper, easier to assemble and more disposable. They also generate waste, both at the start of their life cycles – the petrochemicals industry is a major source of pollution and greenhouse gas emissions – and after disposal.
The biggest domestic use by far for plastic resin is packaging (34 percent in 2017), followed by consumer and institutional goods (20 percent) and construction (17 percent). Many products’ useful lives can be measured in minutes. Others, especially engineered and industrial plastics, have a longer life – up to 35 years for building and construction products.
After disposal, plastic products take anywhere from five to 600 years to break down. Many degrade into micro-plastic fragments that effectively last forever. Rather like J.R.R. Tolkien’s One Ring, plastics can be permanently destroyed only through incineration at extremely high temperatures.
Why the United States recycles so little plastic
Less than 10 percent of discarded plastics entered the recycling stream in the United States in 2015, compared with 39.1 percent in the European Union and 22 percent in China. Another 15 percent of U.S. plastic waste is burned in waste-to-energy facilities. The remaining 75 percent goes to landfills. These figures do not include any dumping or illegal disposal.
Even the most easily recyclable plastics have a lengthy journey from the recycling bin to their final destinations. Many barriers have become painfully apparent since China, which until recently accepted half of all U.S. plastic scrap, implemented its crackdown on March 1, 2018.
First, there are many different types of plastics. Of the seven resin identification codes stamped on the bottom of plastic containers, only 1’s and 2’s are easily recyclable. Public education campaigns have lagged, particularly with respect to cleaning and preparing plastics for recycling. Getting consumers to commit to more stringent systems is critical. But scolding can backfire, as experience with food waste shows.
Another factor is U.S. reliance on single-stream recycling systems, in which all recyclables are placed in the same receptacle. This approach is easier for consumers but produces a mixed stream of materials that is difficult and expensive to sort and clean at recycling facilities.
The United States currently has 633 materials recycling facilities, which can clean, sort and bale a total of 100,000 tons of recyclables per day. Today they are under growing pressure as scrap piles up. Even before China’s restrictions went into effect, materials recycling facilities operators threw out around half of what they received because of contamination. Most are not equipped to meet China’s stringent new contamination standards, and their processing rates have slowed – but garbage production rates have not.
Finally, since China was the U.S. plastic scrap market’s main buyer, its ban has eliminated a key revenue stream for municipal governments. As a result, some waste collection agencies are suspending curbside pickup, while others are raising prices. All 50 states have been affected to some extent.
No silver bullets
Numerous public and private entities are working to find a more viable solution for plastics recycling. They include plastics producers and recyclers, corporations such as Coca-Cola, colleges and universities, foundations, international organizations, advocacy groups and state governments.
Upgrading materials recycling facilities and expanding domestic markets for plastic scrap is an obvious priority but will require large-scale investments. Increasing waste-to-energy incineration is another option. Sweden relies on this approach to maintain its zero waste model.
But incineration is deeply controversial in the United States, where it has declined since 2001, partly due to strong opposition from host communities. Zero-waste and anti-incineration advocates have heavily criticized initiatives such as the Hefty EnergyBag Program, a recent pilot initiative in Omaha, Nebraska to divert plastics to energy production. But small companies like Salt Lake City-based Renewlogy are working to develop newer, cleaner ways to convert plastics to energy.
Efforts to cut plastic use in the United States and other wealthy countries are focusing on single-use products. Initiatives such as plastic straw and bag bans build awareness, but may not significantly reduce the problem of plastic trash by themselves. For example, plastic straws account for only 0.03 percent of the plastic that is likely to enter the oceans in any given year.
To stem ocean plastic pollution, better waste management on land is critical, including steps to combat illegal dumping and manage hard-to-recycle plastics. Examples include preventing BPA leaching from discarded products, dechlorinating polyvinyl chloride products, on-site recycling of 3D printer waste, and making virgin-quality plastic out of used polypropylene.
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The European Union is developing a circular economy platform that contains a multi-part strategy to increase plastics recycling and control waste. It includes making all plastic packaging recyclable by 2030 and reducing leakage of plastic products into the environment. The United States is unlikely to adopt such sweeping policies at the national level. But for cities and states, especially those where support for environmental protection is strong, it could be a more attainable vision.