But for decades, that system has been out of balance. Sunlight continues to pour in, and Earth isn’t releasing enough, either as reflected solar radiation or as emitted infrared radiation. The extra heat trapped around our globe — some 90% of which is stored in the ocean — adds energy to worldwide climate systems and manifests in many ways: higher temperatures, rising sea levels, floods, droughts, more powerful blizzards and hurricanes, and deadlier extreme events.

While climate scientists have warned for a half-century that this was the inevitable result of adding too much carbon dioxide to the atmosphere, so-called climate deniers have continued to suggest that the observed changes might be a fluke — just natural variation.

“Until now, scientists have believed that because of the short observational record, we can’t deduce if the increase in the imbalance is due to humans or climatic ‘noise,'” said Shiv Priyam Raghuraman, a graduate student in atmospheric and oceanic sciences (AOS) at Princeton. “Our study shows that even with the given observational record, it is almost impossible to have such a large increase in the imbalance just by Earth doing its own oscillations and variations.”

He and his co-authors used satellite observations from 2001 to 2020 and found that Earth’s “energy imbalance” is growing. Raghuraman worked with David Paynter of the Geophysical Fluid Dynamics Laboratory (GFDL), a NOAA-funded national laboratory located on Princeton’s Forrestal Campus, and V. “Ram” Ramaswamy, director of GFDL and a lecturer with the rank of professor in geosciences and AOS at Princeton University. Their paper appears today in Nature Communications.

So what has caused the growing energy imbalance?

“We always think, ‘Increasing greenhouse gases means trapping more infrared heat’ — the classic greenhouse effect becomes larger,” said Raghuraman. “This is correct, but the flip side is that the resulting warmer planet now also radiates more infrared heat away to space, so the greenhouse gas heating impact is cancelled. Instead, much of the imbalance increase comes from the fact that we are receiving the same amount of sunlight but reflecting back less, because increased greenhouse gases cause cloud cover changes, less aerosols in the air to reflect sunlight — that is, cleaner air over the U.S. and Europe — and sea-ice decreases.” (Bright white sea ice reflects much more sunlight than sea water, so as sea ice melts, Earth is becoming less reflective.)

In addition, the Princeton and GFDL researchers noted that oceans store 90% of this excess heat. Because of this close relationship between the growing energy imbalance and ocean heating, the Earth’s energy imbalance has important connections to marine health, sea-level rise and the warming of the global climate system. The researchers hope that tracking the historical trends in this energy imbalance and understanding its components will improve the models of future climate change that drive policymaking and mitigation efforts.

“The satellite record provides clear evidence of a human-influenced climate system,” they said. “Knowing that human activity is responsible for the acceleration of planetary heat uptake implies the need for significant policy and societal action to reduce anthropogenic greenhouse gas emissions to curb further increases in Earth’s energy imbalance.”

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Materials provided by Princeton University. Original written by Liz Fuller-Wright. Note: Content may be edited for style and length.

A new article published today warns against relaxing Covid-19 restrictions prematurely.

It describes how we are in an ‘arms race’ with the virus and how rising cases could provide opportunities for it to evolve into even more transmissible variants.

The researchers fear that any new variants could be more virulent, more vaccine resistant, and more dangerous for children and vulnerable groups such as transplant patients.

Lead author and editor in chief of Virulence, Prof Kevin Tyler from UEA’s Norwich Medical School, said: “Over the past 17 months, economies, education and mental well-being have suffered tremendously due to the restrictions imposed in an attempt to stem the spread of the pandemic.

“Although vaccines have weakened the link between infection and mortality, they should not be used as an argument to justify a broad change in policy for countries experiencing an exponential increase in infection numbers.

“This is because most of the world’s population are still unvaccinated, and even in countries with efficient vaccination programmes, a significant proportion of society, particularly children, remain unprotected.

“Relaxing restrictions boosts transmission and allows the virus population to expand, which enhances its adaptive evolutionary potential and increases the risk of vaccine-resistant strains emerging by a process known as antigenic drift.

“Put simply, limiting the spread of Covid-19 as much as possible restricts the number of future deaths by restricting the rate with which new variants arise.

“Successive SARS-CoV-2 variants such as the Alpha and Delta variants, have displaced one another since the outbreak.

“Slowing down the rate of new variant emergence requires us to act fast and decisively, reducing the number of infected people including children with vaccines and in combination with other public health policies.

“In most cases, children are not vaccinated against Covid-19 because the risk to them becoming seriously ill is very low. But new strains may evolve with higher transmissibility in children, and vaccinating children may become necessary to control the emergence of new variants.

“In other words, a policy of relaxing restrictions while children are not vaccinated, risks inadvertently selecting for virulent variants that are better able to infect children and are also more problematic in vulnerable groups.

“Children may be particularly at risk because they are the only group that has remained unvaccinated. But there is no guarantee that the virus won’t evolve the ability to infect children too, and the data shows that new variants are relatively more often found in younger age groups.

“Only when a large proportion of the world’s population is vaccinated, or has acquired immunity from infection, can we relax other social measures.

Co-lead author and evolutionary biologist Prof Cock Van Oosterhout, from UEA’s School of Environmental Sciences, said: “We have an arms race on our hands.

“On the human side, the arms race is fought with vaccines, new technology such as the NHS Covid-19 App, and our behavioural change, but the virus fights back by adapting and evolving.

“It is unlikely we will get ahead in this arms race unless we can significantly reduce the population size of the virus.

“But given that the infection rate is about the same now as it was during the first wave, we are pretty much ‘at evens’ with this virus.

And as with many other coevolutionary arms races, there are no winners.

“This is what evolutionary biologists mean when we say that coevolution is a ‘zero-sum game’. But what you cannot do is suddenly drop your guard in the middle of an arms race. That gives your opponent — the virus — a real advantage. So we must continue doing the things we have been doing for the past 18 months, particularly in countries where the number of infected people is increasing.

“Entrusting public health measures to personal responsibility is a laissez-faire approach that many governments are now taking towards Covid-19 management.

“During exponential transmission of virus, we need an ongoing, mandatory public health policy that includes social distancing and the compulsory wearing of facemasks in crowded indoor spaces such as shops and on public transport.

“Our current vaccination programmes alone will not end the pandemic and scientific evidence suggests that we can only safely start to relax social restrictions when the R number is below one,” he added.

Co-author and director of the Earlham Institute (EI), Prof Neil Hall, said: “As long as there are large numbers of unvaccinated people around the world transmitting the virus, we’re all at risk.

“High numbers of Covid-19 cases increase the likelihood the virus will evolve to become more virulent, more transmissible, or capable of evading vaccines. It’s critical we continue using public health measures to bring transmission rates down. We have to co-exist with caution — if we ignore global health policies which have proven to reduce infection, the virus will further adapt.

“When we weigh up the benefits and risks in vaccinating young people, we have to consider the impact on wider society too. The current approach to protecting young people seems to be letting them reach herd immunity through infection. Every day that approach continues, we give the virus the upper hand and prolong this pandemic — increasing the burden on healthcare systems and economies.”

‘COVID-19 adaptive evolution during the pandemic — Implications of new SARS-CoV-2 variants on public health policies’ is published in the journal Virulence on July 27, 2021.

The article was led by researchers at UEA in collaboration with Norwich Research Park colleagues at the Earlham Institute, as well as it the University of Pittsburgh, the University of California Davis, the University of Minnesota Twin Cities, and King Abdul Aziz University, Jeddah, Saudi Arabia.

Saeideh Esmaeili, who graduated from UW’s Program in Ecology in December 2020 and is now a postdoctoral assistant at Colorado State University, is the lead author of a paper that appears in the journal Ecology Letters. It explores the foraging behavior of 30 species of ungulates across North America, Europe, Africa and the Middle East, ranging from elk and mule deer in Wyoming to gazelles, impalas, reindeer, wildebeest, wild asses and zebras.

“By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified the effect of body size and digestive system in determining movements of 30 populations of ungulates,” Esmaeili says.

Other UW researchers who participated are Shannon Albeke, Jeff Beck, Jake Goheen, Matt Kauffman and Jerod Merkle, along with Hall Sawyer, of Laramie-based Western EcoSystems Technology Inc. Goheen was Esmaeili’s Ph.D. adviser.

The research adds nuance to a long-held hypothesis that ungulates choose to forage on grasses and other plants when the vegetation is at an intermediate stage of growth, so as to maximize energy intake. This is called the “forage maturation hypothesis.” Plants are most digestible at the beginning of the growing season; however, because they are small during this time, biomass is low. As plants mature, they gain biomass, but they become harder to digest.

The ungulates that were part of this study include both ruminants, such as deer and elk, which acquire nutrients by fermenting plants in a specialized stomach prior to digestion; and equids, such as horses and zebras, which don’t have such specialized stomachs.

Most notably, the scientists found that smaller-bodied ruminants forage primarily for the highest energy intake, while equids — which tend to be larger — choose to forage in areas close to surface water, with less attention to forage condition. That’s likely because equids don’t conserve water as efficiently as ruminants and proportionally excrete more water. The research also confirmed that ruminants’ ability to process higher-biomass forage increases with the species’ size.

A primary conclusion of the research is that, while the forage maturation hypothesis largely holds true, there is some variation based upon ungulates’ body size and digestive systems.

“The forage characteristics that influence population persistence of free-ranging ungulates should differ according to body size and digestive system, such that access to a combination of resource gradients is key to maintaining viable populations of diverse free-ranging ungulates across the globe,” the scientists conclude.

Other institutions, organizations and agencies whose researchers participated in the project include Virginia Tech University; Yale University; the U.S. Geological Survey; Colorado State University; the University of Washington; the Wildlife Conservation Society; France’s University of Montpellier; South Africa’s University of Pretoria; Germany’s Senckenberg Biodiversity and Climate Research Centre; Mongolia’s Hustai National Park Trust; the Cary Institute of Ecosystem Studies; the University of British Columbia; the Minnesota Zoo; Iran’s Isfahan University of Technology; Japan’s Tottori University; the Norwegian Institute for Nature Research; Austria’s University of Veterinary Medicine; the Inland Norway University of Applied Sciences; the Mongolian Academy of Sciences; and the Smithsonian Conservation Biology Institute.

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Materials provided by University of Wyoming. Note: Content may be edited for style and length.

The longitudinal study, appearing in The Economic Journal, measured the risk preferences of 5,300 couples in Germany from 2004 to 2017. Participants in the survey — conducted annually by the German Socio-Economic Panel — were asked how willing they were to take risks when it comes to careers, sports, driving and financial matters.

After controlling for an array of household characteristics, such as the wife’s and husband’s education level, religion, region of origin, cultural background and more, the author found differences in risk preferences are the biggest predictor of marital separation in the long run.

Couples who had the most dissimilar risk attitudes are twice as likely to divorce, compared to couples with the most similar preferences. Additionally, of all the risk categories listed in the survey, differences in financial risks were the strongest predictor of divorce.

“Arguing about money is typically cited as a reason for divorce, but a main potential driver of these fights is differences in risk attitudes,” said the study’s author, Marta Serra-Garcia, associate professor of economics and strategy at the Rady School. “Risk attitudes determine investment decisions, such as housing for the family. If spouses have different risk preferences, they will often disagree on common and very important investments in the marriage.”

The findings reveal that couples who differ on savings and investment decisions are less likely to own a home and/or have their home renovated.

Serra-Garcia points out with both parties pooling their resources, couples make significant gains from marriage.

“On one hand, households share common goods, such as housing, and for that similarity in risk attitudes is optimal,” she said. “On the other hand, households share two sources of income and income is typically risky. Since spouses pool their incomes, if one has a less a reliable stream than the other, differences in risk attitudes can be optimal because they can ‘insure’ each other, but this can also be a source of tension for marriages.”

The study also reveals that newly formed couples became more alike over time, demonstrating that within a household, attitudes are not fixed.

For example, in tough financial times, such as the great recession of 2009, most couples become more risk averse. The study finds that couples who became more similar during this time were less likely to divorce later.

“Preference assimilation could be a mechanism for resolving conflict within marriages,” Serra-Garcia said. “As a result, these couples have a stronger likelihood of staying together.”

The results from the study could have implications for the dating website industry. Over one third of couples in the U.S. meet online where users are able to learn about an individual’s characteristics before the dating process begins.

“Online dating websites often design algorithms that attempt to find the optimal match,” Serra-Garcia said. “If such websites suggested matches between individuals who are similar in their risk attitudes, that could decrease the likelihood that if a couple forms, it will dissolve in the future.”

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Materials provided by University of California – San Diego. Original written by Christine Clark. Note: Content may be edited for style and length.