‘Powerful Evidence’ of Global Warming’s Effect on Seasons Found in Troposphere
By Daisy Dunne
Scientists studying the troposphere—the lowest level of the atmosphere—have found "powerful evidence" that climate change is altering seasonal temperatures.
A study published in Science finds that climate change has caused an increase in the difference between summer and winter temperatures across North America and Eurasia over the past four decades.
This could be the result of summer temperatures warming at a faster rate than winter temperatures in these parts of the world, the researchers say.
The findings show the "substantial human influence on Earth's climate, affecting not only global averages, but also local and seasonal changes," another scientist says.
Most of the world's weather originates in the troposphere, a second scientist tells Carbon Brief, meaning that changes to seasonal temperatures could be affecting the likelihood of extreme weather events, such as flooding and drought.
Evidence shows that the seasons are changing. In Europe, for example, analysis of the first-emergence dates of more than 500 plant species shows that the first day of spring has advanced by six to eight days in the past three decades.
However, working out to what extent seasonal changes can be explained by climate change—rather than natural climate variability, caused by phenomena such as El Niño—presents more of a challenge.
To quantify the influence of climate change versus natural variability, scientists often carry out "attribution" studies.
The new study is the first to assess how climate change could be influencing seasonal temperature changes in the troposphere—a layer that covers roughly the first 17 kilometers (approximately 10.6 miles) of the atmosphere above the earth.
"Our results suggest that attribution studies with the changing seasonal cycle provide powerful evidence for a significant human effect on Earth's climate."
For the study, the researchers analyzed atmospheric temperature data recorded by satellites throughout the summer and winter months from 1979-2016. (Carbon Brief has published an explainer on how satellite temperature records compare with measurements at the earth's surface.)
The map below shows how the difference between summer and winter temperatures, expressed as an average per decade, has changed across the world.
On the map, dark red indicates where the difference between summer and winter temperatures have grown larger, while dark blue shows where the difference has grown smaller.
Temperature difference between summer and winter months (per decade) from 1979-2016. Red shows a large temperature difference between the seasons, while blue shows a small temperature difference. Source: Randel (2018) Data source: Santer et al. (2018)
The map shows that the difference between summer and winter temperatures has increased the most in mid-latitude regions, particularly in the northern hemisphere.
This is because, in these regions, atmospheric summer temperatures are increasing at a faster rate than winter temperatures—causing the disparity between the two seasons to grow larger and larger, the researchers say.
The northern hemisphere has experienced more summertime warming than the southern hemisphere because it contains more land, the researchers say. The presence of land means that less heat can be absorbed by the ocean—leading to amplified atmospheric warming.
The map also indicates that the eastern edges of both North America and Eurasia have experienced the greatest amounts of warming. This could be because, during the winter in these regions, warm air masses are carried from east to west—leading to milder winters along western continental margins, the researchers say.
Changes in temperatures are not as pronounced around the tropics because this region is not highly seasonal, the researchers say. Instead, the seasons in tropical regions are typically defined by rainfall ("wet" and "dry," for example), rather than by temperature.
In contrast, the difference between summer and winter temperatures around the poles has shrunk over the past four decades, the map shows. In these regions, winter temperatures are rising faster than summer temperatures, the research finds.
In the Arctic, this winter warming is partly influenced by the diminishing presence of sea ice during summer months, the researchers say. With less sea ice present, the ocean absorbs more heat—which is later released during the winter, the researchers say.
The reason that winter atmospheric warming may have accelerated above Antarctica is less clear. However, previous research suggests that the presence of polar clouds in the stratosphere (which sits above the troposphere) could be playing a role.
'Substantial Human Influence'
To understand to what extent the observed seasonal changes were influenced by human-caused climate change, the researchers compared the satellite results to climate models.
The model simulations, which ran from 1979-2016, included a range of natural factors that can influence tropospheric temperature, including the cooling effect of volcanic eruptions and aerosols. To include the impact of human-caused climate change, the researchers used a "business-as-usual" emissions scenario known as RCP8.5.
The results show that only simulations that include the impact of human-caused climate change could correctly predict the patterns of seasonal temperature change recorded by the satellites.
This indicates that humans are having a "substantial influence" on the temperatures in the troposphere, said Dr. William Randel, a senior scientist at the National Center for Atmospheric Research, who was not involved in the research. In an accompanying perspectives article, he writes:
"[The] findings provide further markers of a substantial human influence on Earth's climate, affecting not only global averages, but also local and seasonal changes."
However, it is not clear how temperature changes in the troposphere could affect conditions at the land surface, he adds:
"The connection between changes at the surface and the free troposphere awaits explanation."
One possible effect could be changes to the timing and likelihood of extreme weather events, said professor Neil Harris, head of the Centre for Environment and Agricultural Informatics at Cranfield University, who was not involved in the research. He told Carbon Brief:
"The paper significantly increases confidence that the observed changes in the troposphere—where all our weather is—are consistent with models and that they are of human origin. This gives more confidence in the existing findings of an increase frequency of extreme weather, such as more intense rainfall and more extreme summer hot spells."
Solar Eclipse: Why the Sun Is Not Responsible for Recent Climate Change https://t.co/LukE7BHXKE #SolarEclipse2017 #Eclipse2017 @NASA @SpaceX— EcoWatch (@EcoWatch)1503321539.0
Reposted with permission from our media associate Carbon Brief.
Thousands of Superfund sites exist around the U.S., with toxic substances left open, mismanaged and dumped. Despite the high levels of toxicity at these sites, nearly 21 million people live within a mile of one of them, according to the U.S. Environmental Protection Agency (EPA).
Currently, more than 1,300 Superfund sites pose a serious health risk to nearby communities. Based on a new study, residents living close to these sites could also have a shorter life expectancy.
Published in Nature Communications, the study, led by Hanadi S. Rifai, a professor of civil and environmental engineering at the University of Houston, and a team of researchers, found that living in nearby zip codes to Superfund sites resulted in a decreased life expectancy of more than two months, the University of Houston reported.
"We have ample evidence that contaminant releases from anthropogenic sources (e.g., petrochemicals or hazardous waste sites) could increase the mortality rate in fence-line communities," Rifai told the University of Houston. "Results showed a significant difference in life expectancy among census tracts with at least one Superfund site and their neighboring tracts with no sites."
The study pulled data from 65,000 census tracts – defined geographical regions – within the contiguous U.S., The Guardian reported. With this data, researchers found that for communities that are socioeconomically challenged, this life expectancy could decrease by up to a year.
"It was a bit surprising and concerning," Rifai told The Guardian. "We weren't sure [when we started] if the fact that you are socioeconomically challenged would make [the Superfund's effects] worse."
The research team, for example, found that the presence of a Superfund site in a census tract with a median income of less than $52,580 could reduce life expectancy by seven months, the University of Houston reported.
Many of these toxic sites were once used as manufacturing sites during the Second World War. Common toxic substances that are released from the sites into the air and surface water include lead, trichlorethylene, chromium, benzene and arsenic – all of which can lead to health impacts, such as neurological damage among children, The Union of Concerned Scientists wrote in a blog.
"The EPA has claimed substantial recent progress in Superfund site cleanups, but, contrary to EPA leadership's grandiose declarations, the backlog of unfunded Superfund cleanups is the largest it has been in the last 15 years," the Union wrote.
Delayed cleanup could become increasingly dangerous as climate change welcomes more natural hazards, like wildfires and flooding. According to a Government Accountability Office report, for example, climate change could threaten at least 60 percent of Superfund sites in the U.S., AP News reported.
During the summer of 2018, a major wildfire took over the Iron Mountain Superfund site near Redding, CA, ruining wastewater treatment infrastructure that is responsible for capturing 168 million gallons of acid mine drainage every month, NBC News reported.
"There was this feeling of 'My God. We ought to have better tracking of wildfires at Superfund locations,'" Stephen Hoffman, a former senior environmental scientist at the EPA, told NBC News. "Before that, there wasn't a lot of thought about climate change and fire. That has changed."
In the study, researchers also looked at the impacts of floodings on Superfund sites, which could send toxins flowing into communities and waterways.
"When you add in flooding, there will be ancillary or secondary impacts that can potentially be exacerbated by a changing future climate," Rifai told the University of Houston. "The long-term effect of the flooding and repetitive exposure has an effect that can transcend generations."
- Biden Faces Pressure to Tackle 'Unfunded' Toxic Waste Sites ... ›
- Do You Live Near One of the 1,300 Most Toxic Sites in America ... ›
- EPA Adds Prison Locations to Its Environmental Justice Mapping ... ›
- EPA: Houston Superfund Site Leaked Toxic Chemicals After Harvey ... ›
A weather research station on a bluff overlooking the sea is closing down because of the climate crisis.
The National Weather Service (NWS) station in Chatham, Massachusetts was evacuated March 31 over concerns the entire operation would topple into the ocean.
"We had to say goodbye to the site because of where we are located at the Monomoy Wildlife Refuge, we're adjacent to a bluff that overlooks the ocean," Boston NWS meteorologist Andy Nash told WHDH at the time. "We had to close and cease operations there because that bluff has significantly eroded."
Chatham is located on the elbow of Cape Cod, a land mass extending out into the Atlantic Ocean that has been reshaped and eroded by waves and tides over tens of thousands of years, The Guardian explained. However, sea level rise and extreme weather caused by the climate crisis have sped that change along.
"It's an extremely dynamic environment, which is obviously a problem if you are building permanent infrastructure here," Andrew Ashton, an associate scientist at Cape-Cod based Woods Hole Oceanographic Institution, told The Guardian. "We are putting our foot on the accelerator to make the environment even more dynamic."
This was the case with the Chatham weather station. It used to be protected from the drop into the ocean by about 100 feet of land. However, storm action in 2020 alone washed away as much as six feet of land a day.
"We'd know[n] for a long time there was erosion but the pace of it caught everyone by surprise," Nash told The Guardian. "We felt we had maybe another 10 years but then we started losing a foot of a bluff a week and realized we didn't have years, we had just a few months. We were a couple of storms from a very big problem."
The Chatham station was part of a network of 92 NWS stations that monitor temperature, pressure, humidity, wind speed and direction and other data in the upper atmosphere, The Cape Cod Chronicle explained. The stations send up radiosondes attached to weather balloons twice a day to help with weather research and prediction. The Chatham station, which had been observing this ritual for the past half a century, sent up its last balloon the morning of March 31.
"We're going to miss the observations," Nash told The Cape Cod Chronicle. "It gives us a snapshot, a profile of the atmosphere when the balloons go up."
The station was officially decommissioned April 1, and the two buildings on the site will be demolished sometime this month. The NWS is looking for a new location in southeastern New England. In the meantime, forecasters will rely on data from stations in New York and Maine.
Nash said the leavetaking was bittersweet, but inevitable.
"[M]other nature is evicting us," he told The Cape Cod Chronicle.
By Douglas Broom
- If online deliveries continue with fossil-fuel trucks, emissions will increase by a third.
- So cities in the Netherlands will allow only emission-free delivery vehicles after 2025.
- The government is giving delivery firms cash help to buy or lease electric vehicles.
- The bans will save 1 megaton of CO2 every year by 2030.
Cities in the Netherlands want to make their air cleaner by banning fossil fuel delivery vehicles from urban areas from 2025.
"Now that we are spending more time at home, we are noticing the large number of delivery vans and lorries driving through cities," said Netherlands environment minister Stientje van Veldhoven, announcing plans to ban all but zero-emission deliveries in 14 cities.
"The agreements we are setting down will ensure that it will be a matter of course that within a few years, supermarket shelves will be stocked, waste will be collected, and packages will arrive on time, yet without any exhaust fumes and CO2 emissions," she added.
She expects 30 cities to announce zero emission urban logistics by this summer. City councils must give four years' notice before imposing bans as part of government plans for emission-free road traffic by 2050. The city bans aim to save 1 megaton of CO2 each year by 2030.
Help to Change
To encourage transport organizations to go carbon-free, the government is offering grants of more than US$5,900 to help businesses buy or lease electric vehicles. There will be additional measures to help small businesses make the change.
The Netherlands claims it is the first country in the world to give its cities the freedom to implement zero-emission zones. Amsterdam, Rotterdam and Utrecht already have "milieuzones" where some types of vehicles are banned.
Tilburg, one of the first wave of cities imposing the Dutch ban, will not allow fossil-fuelled vehicles on streets within its outer ring road and plans to roll out a network of city-wide electric vehicle charging stations before the ban comes into effect in 2025.
"Such initiatives are imperative to improve air quality. The transport of the future must be emission-free, sustainable, and clean," said Tilburg city alderman Oscar Dusschooten.
Europe Takes Action
Research by Renault shows that many other European cities are heading in the same direction as the Netherlands, starting with Low Emission Zones of which Germany's "Umweltzone" were pioneers. More than 100 communes in Italy have introduced "Zonas a traffico limitato."
Madrid's "zona de baja emisión" bans diesel vehicles built before 2006 and petrol vehicles from before 2000 from central areas of the city. Barcelona has similar restrictions and the law will require all towns of more than 50,000 inhabitants to follow suit.
Perhaps the most stringent restrictions apply in London's Ultra Low Emission Zone (ULEZ), which charges trucks and large vehicles up to US$137 a day to enter the central area if they do not comply with Euro 6 emissions standards. From October, the ULEZ is being expanded.
Cities are responsible for around 75% of CO2 emissions from global final energy use, according to the green thinktank REN21 - and much of these come from transport. Globally, transport accounts for 24% of world CO2 emissions.
The Rise of Online Shopping
Part of the reason for traffic in urban areas is the increase in delivery vehicles, as online shopping continues to grow. Retailer ecommerce sales are expected to pass $5billion in 2022, according to eMarketer.
The World Economic Forum's report The Future of the Last-Mile Ecosystem, published in January 2020, estimates that e-commerce will increase the number of delivery vehicles on the roads of the world's 100 largest cities by 36% by 2030.
If all those vehicles burn fossil fuels, the report says emissions will increase by 32%. But switching to all-electric delivery vehicles would cut emissions by 30% from current levels as well as reducing costs by 25%, the report says.
Other solutions explored in the report include introducing goods trams to handle deliveries alongside their passenger-carrying counterparts and increased use of parcel lockers to reduce the number of doorstep deliveries.
Reposted with permission from the World Economic Forum.
The bill, SB467, would have prohibited fracking and other controversial forms of oil extraction. It would also have banned oil and gas production within 2,500 feet of a home, school, hospital or other residential facility. The bill originally set the fracking ban for 2027, but amended it to 2035, The AP reported.
"Obviously I'm very disappointed," State Sen. Scott Wiener (D-San Francisco), one of the bill's two introducers, told the Los Angeles Times. "California really has not done what it needs to do in terms of addressing the oil problem. We have communities that are suffering right now, and the Legislature has repeatedly failed to act."
The bill was introduced after California Gov. Gavin Newsom said he would sign a fracking ban if it passed the legislature, though his administration has continued to issue permits in the meantime, Forbes reported. Newsom has also spoken in favor of a buffer zone between oil and gas extraction and places where people live and learn, according to the Los Angeles Times. The latter is a major environmental justice issue, as fossil fuel production is more likely to be located near Black and Latinx communities.
Urban lawmakers who want California to lead on the climate crisis supported the bill, while inland lawmakers in oil-rich areas concerned about jobs opposed it. The oil and gas industry and trade unions also opposed the bill.
This opposition meant the bill failed to get the five votes it needed to move beyond the Senate's Natural Resources and Water Committee. Only four senators approved it, while Democrat Sen. Susan Eggman of Stockton joined two Republicans to oppose it, and two other Democrats abstained.
Eggman argued that the bill would have forced California to rely on oil extracted in other states.
"We're still going to use it, but we're going to use it from places that produce it less safely," Eggman told The AP. She also said that she supported the transition away from fossil fuels, but thought the bill jumped the gun. "I don't think we're quite there yet, and this bill assumes that we are," she added.
Historically, California has been a major U.S. oil producer. Its output peaked in 1986 at 1.1 million barrels a day, just below Texas and Alaska, according to Forbes. However, production has declined since then making it the seventh-most oil-producing state.
Still, California's fossil fuel industry is at odds with state attempts to position itself as a climate leader.
"There is a large stain on California's climate record, and that is oil," Wiener said Tuesday, according to The AP.
Wiener and Democrat co-introducer Sen. Monique Limón from Santa Barbara vowed to keep fighting.
"While we saw this effort defeated today, this issue isn't going away," they wrote in a joint statement. "We'll continue to fight for aggressive climate action, against harmful drilling, and for the health of our communities."
- What the Industry Doesn't Want You to Know About Fracking ... ›
- Final EPA Study Confirms Fracking Contaminates Drinking Water ... ›
- Pennsylvania Fracking Water Contamination Much Higher Than ... ›
By Brett Wilkins
As world leaders prepare for this November's United Nations Climate Conference in Scotland, a new report from the Cambridge Sustainability Commission reveals that the world's wealthiest 5% were responsible for well over a third of all global emissions growth between 1990 and 2015.
The report, Changing Our Ways: Behavior Change and the Climate Crisis, found that nearly half the growth in absolute global emissions was caused by the world's richest 10%, with the most affluent 5% alone contributing 37%.
"In the year when the UK hosts COP26, and while the government continues to reward some of Britain's biggest polluters through tax credits, the commission report shows why this is precisely the wrong way to meet the UK's climate targets," the report's introduction states.
The authors of the report urge United Kingdom policymakers to focus on this so-called "polluter elite" in an effort to persuade wealthy people to adopt more sustainable behavior, while providing "affordable, available low-carbon alternatives to poorer households."
The report found that the "polluter elite" must make "dramatic" lifestyle changes in order to meet the UK's goal — based on the Paris climate agreement's preferential objective — of limiting global heating to 1.5°C, compared with pre-industrial levels.
In addition to highlighting previous recommendations — including reducing meat consumption, reducing food waste, and switching to electric vehicles and solar power — the report recommends that policymakers take the following steps:
- Implement frequent flyer levies;
- Enact bans on selling and promoting SUVs and other high polluting vehicles;
- Reverse the UK's recent move to cut green grants for homes and electric cars; and
- Build just transitions by supporting electric public transport and community energy schemes.
"We have got to cut over-consumption and the best place to start is over-consumption among the polluting elites who contribute by far more than their share of carbon emissions," Peter Newell, a Sussex University professor and lead author of the report, told the BBC.
"These are people who fly most, drive the biggest cars most, and live in the biggest homes which they can easily afford to heat, so they tend not to worry if they're well insulated or not," said Newell. "They're also the sort of people who could really afford good insulation and solar panels if they wanted to."
Newell said that wealthy people "simply must fly less and drive less. Even if they own an electric SUV, that's still a drain on the energy system and all the emissions created making the vehicle in the first place."
"Rich people who fly a lot may think they can offset their emissions by tree-planting schemes or projects to capture carbon from the air," Newell added. "But these schemes are highly contentious and they're not proven over time."
The report concludes that "we are all on a journey and the final destination is as yet unclear. There are many contradictory road maps about where we might want to get to and how, based on different theories of value and premised on diverse values."
"Promisingly, we have brought about positive change before, and there are at least some positive signs that there is an appetite to do what is necessary to live differently but well on the planet we call home," it states.
The new report follows a September 2020 Oxfam International study that revealed the wealthiest 1% of the world's population is responsible for emitting more than twice as much carbon dioxide as the poorest 50% of humanity combined.
Reposted with permission from Common Dreams.
- Small Percentage of Frequent Flyers Are Driving Global Emissions ... ›
- World's Richest People Gained $1.8 Trillion in 2020 - EcoWatch ›
- Tourism Responsible for 8% of Global Greenhouse Gas Emissions ... ›