While there are many studies that focus on nitrogen and phosphorus losses, very few systematic reviews exist that aim to understand the impacts of site-specific conditions and management practices on annual nutrient losses in subsurface and surface runoff. To address these research gaps, EPA researchers gathered hundreds of peer-reviewed literature sources to conduct twostudies that analyzed existing data from the Lake Erie Basin and 12 states in the greater Midwest U.S. These regions served as good research areas since the land is primarily used for crops – mainly corn, soybean, and wheat.
The deadly tornado outbreak that tore through communities from Arkansas to Illinois on the night of Dec. 10-11, 2021, was so unusual in its duration and strength, particularly for December, that a lot of people including the U.S. president are asking what role climate change might have played – and whether tornadoes will become more common in a warming world.
Both questions are easier asked than answered, but research is offering new clues.
I’m an atmospheric scientist who studies severe convective storms like tornadoes and the influences of climate change. Here’s what scientific research shows so far.
Climate models can’t see tornadoes yet – but they can recognize tornado conditions
To understand how rising global temperatures will affect the climate in the future, scientists use complex computer models that characterize the whole Earth system, from the Sun’s energy streaming in to how the soil responds and everything in between, year to year and season to season. These models solve millions of equations on a global scale. Each calculation adds up, requiring far more computing power than a desktop computer can handle.
To project how Earth’s climate will change through the end of the century, we currently have to use a broad scale. Think of it like the zoom function on a camera looking at a distant mountain. You can see the forest, but individual trees are harder to make out, and a pine cone in one of those trees is too tiny to see even when you blow up the image. With climate models, the smaller the object, the harder it is to see.
Tornadoes and the severe storms that create them are far below the typical scale that climate models can predict.
What we can do instead is look at the large-scale ingredients that make conditions ripe for tornadoes to form.
Two key ingredients for severe storms are (1) energy driven by warm, moist air promoting strong updrafts, and (2) changing wind speed and direction, known as wind shear, which allows storms to become stronger and longer-lived. A third ingredient, which is harder to identify, is a trigger to get storms to form, such as a really hot day, or perhaps a cold front. Without this ingredient, not every favorable environment leads to severe storms or tornadoes, but the first two conditions still make severe storms more likely.
By using these ingredients to characterize the likelihood of severe storms and tornadoes forming, climate models can tell us something about the changing risk.
Rising global temperatures are driving significant changes for seasons that we traditionally think of as rarely producing severe weather. Stronger increases in warm humid air in fall, winter and early spring mean there will be more days with favorable severe thunderstorm environments – and when these storms occur, they have the potential for greater intensity.
We are already seeing evidence in the past few decades of shifts toward conditions more favorable for severe storms in the cooler seasons, while the summertime likelihood of storms forming is decreasing.
For tornadoes, things get trickier. Even in an otherwise spot-on forecast for the next day, there is no guarantee that a tornado will form. Only a small fraction of the storms produced in a favorable environment will produce a tornado at all.
Several simulations have explored what would happen if a tornado outbreak or a tornado-producing storm occurred at different levels of global warming. Projections suggest that stronger, tornado-producing storms may be more likely as global temperatures rise, though strengthened less than we might expect from the increase in available energy.
The impact of 1 degree of warming
Much of what we know about how a warming climate influences severe storms and tornadoes is regional, chiefly in the United States. Not all regions around the globe will see changes to severe storm environments at the same rate.
In a recent study, colleagues and I found that the rate of increase in severe storm environments will be greater in the Northern Hemisphere, and that it increases more at higher latitudes. In the United States, our research suggests that for each 1 degree Celsius (1.8 F) that the temperatures rises, a 14-25% increase in favorable environments is likely in spring, fall and winter, with the greatest increase in winter. This is driven predominantly by the increasing energy available due to higher temperatures. Keep in mind that this is about favorable environments, not necessarily tornadoes.
What does this say about December’s tornadoes?
To answer whether climate change influenced the likelihood or intensity of tornadoes in the December 2021 outbreak, it remains difficult to attribute any single event like this one to climate change. Shorter-term influences like the El Niño-Southern Oscillation may also complicate the picture.
There are certainly signals pointing in the direction of a stormier future, but how this manifests for tornadoes is an open area of research.
From record-breaking heat waves to massive wildfires, floods and long-running drought, the impacts of climate change across the U.S. have been impossible to ignore in 2021. While conditions vary from one region to another, it is clear that no part of the nation will be unaffected.
I work in Southern California, a region long famous for its temperate climate. For the past two years, my colleagues and I at the USC Dornsife Center for Economic and Social Research have been surveying a representative internet panel of 1,800 Los Angeles County residents to better understand how social and environmental factors such as climate change affect people’s well-being.
For areas of the U.S. that have yet to feel the full force of rising temperatures, the results of our latest USC Dornsife-Union Bank LABarometersurvey show what kinds of challenges they can expect. In Los Angeles the climate crisis is already reducing the quality of residents’ lives. And our findings clearly show that its impacts are falling disproportionately on residents who are young, poor, Black and Hispanic.
Growing numbers are staying indoors
The COVID-19 pandemic wasn’t the only threat to public health in 2021. Wildfires burned more than 6.8 million acres across the U.S. after consuming 10.1 million acres in 2020. And our data shows that many L.A. residents stay home when wildfires threaten air quality in their neighborhoods.
According to our survey, 50% of Angelenos avoided going outdoors at some point between July 2020 and July 2021 because of air quality concerns from a nearby wildfire, up from 30% in the previous year. We expect this number will continue to grow as wildfires increase in frequency and size. A recent climate vulnerability assessment predicts that by 2050 there could be a 40% increase in area burned by wildfires in Los Angeles.
Large-scale wildfires have become annual events in California in an ever-expanding fire season. Los Angeles residents have received warnings about the health risks of wildfire smoke, which can cause lung damage and worsen cardiovascular problems like heart disease and stroke with heavy or long-term exposure. These health risks may explain why Angelenos are increasingly curtailing outdoor activities when wildfires are burning.
By 2050, Los Angeles expects up to a tenfold increase in the frequency of extreme heat waves. This equates to over five heat waves per year compared with the historic average of less than one per year.
This forecast poses troubling implications for health equity in the region. According to our data, vulnerability to heat is unequally distributed across the population. Black residents are significantly more likely than white residents to be exposed to heat at home and at work.
At home, rates of access to air conditioning are heavily stratified by race. Asian and white residents are the most likely to report having air conditioning in their homes (90% and 87%, respectively), while Black residents are the least likely to have this amenity (66%).
At work, approximately 27% of Black residents report working outdoors without cover – for example, from a tent or booth – compared with 18% of Hispanic residents, 15% of white residents and 10% of Asian residents. Prolonged heat exposure, especially without the opportunity to cool off overnight, is a serious health risk.
Expensive and stressful
Our survey also reveals that climate change is affecting Angelenos’ financial and mental health. According to self-reported data, nearly 10% of residents saw an increase in their utility expenses, 4.4% lost income and 3.1% suffered health problems because of a natural disaster such as wildfire, flooding or extreme heat in the past year.
Living in Los Angeles has never been risk-free: Earthquakes are a well-known hazard here and elsewhere in California. But climate change is magnifying other threats, such as wildfires, droughts and heat waves. All of these events can damage property, threaten residents’ health and safety and force some people from their homes.
Natural disasters can also trigger various forms of psychological distress. Over 1 in 4 Angelenos reported experiencing some form psychological distress over the past 12 months because of a natural disaster, including anxiety, depression, prolonged fatigue or high stress.
These mental health impacts were most pronounced among young and low-income residents. Angelenos with a household income below $30,000 per year were almost twice as likely as those with higher incomes to report psychological distress due to a natural disaster. Likewise, compared with Angelenos ages 60 and older, more than twice as many Angelenos under age 40 reported experiences of psychological distress due to a natural disaster.
The climate crisis is a social and economic crisis
As cities and counties around the country brace for more extreme climate conditions, our findings in Los Angeles show that extreme weather can have serious social and economic impacts. In the span of just the past year, climate change has left millions of Americans isolated and financially or psychologically distressed.
Adapting to these risks isn’t just a matter of weatherizing homes and educating the public about climate hazards. Local governments also need to prepare for inevitable strains on social and health care systems as climate conditions make it increasingly difficult for people to meet their most basic needs.
Oceana analyzed e-commerce packaging data and found that Amazon generated 599 million pounds of plastic packaging waste in 2020. This is a 29% increase of Oceana’s 2019 estimate of 465 million pounds. The report also found that Amazon’s estimated plastic packaging waste, in the form of air pillows alone, would circle the Earth more than 600 times.
By combining the e-commerce packaging data with findings from a recent study published in Science, Oceana estimates that up to 23.5 million pounds of Amazon’s plastic packaging waste entered and polluted the world’s waterways and oceans in 2020, the equivalent of dumping a delivery van payload of plastic into the oceans every 67 minutes.