Top science stories of 2023

As 2023 rolls to a close, Knowable Magazine has looked back over its articles and canvassed editorial committee members from the 51 academic journals — covering analytical chemistry to vision science — published by Knowable’s parent company, Annual Reviews. From good news to bad, from novel vaccines to insect invaders, this year left us with much to ponder. Here we present 12 newsworthy developments from 2023.

Jabs for hope

Hot on the heels of the Covid-19 vaccine success story (including updated jabs that target Omicron subvariants of the rapidly shifting virus), 2023 saw the greenlighting of several new vital vaccines. Abrysvo and Arexvy, the first vaccines against respiratory syncytial virus (RSV), a cold-like virus that can be dangerous for the old or the young, are now available in the United States and elsewhere. And the World Health Organization has recommended a second malaria vaccine, R21, following RTS,S in 2021. RTS,S has already been given to nearly 2 million children in Africa; the new vaccine is about half the price.

This double hit against malaria is a “huge win” for kids, says Matthew Laurens, a pediatric infectious disease specialist at the University of Maryland School of Medicine in Baltimore, who wrote about malaria vaccines in a 2022 opinion article for Knowable. “Like Covid-19, we need multiple malaria vaccines if we’re to succeed in combating this deadly disease.”

Scary smarts

One of the biggest newsmakers of the year was artificial intelligence (AI). San Francisco tech company OpenAI’s conversational bot ChatGPT, first launched in November 2022, was estimated to have more than 100 million monthly users by January 2023. People were simultaneously impressed and appalled by the capacity of AI based on deep learning (a technique inspired by the human brain) to write everything from poetry to class essays and research papers. “In terms of public interest, I have not seen anything like this in my 30-year career,” says Colin Phillips, a psycholinguist at the University of Maryland and co-editor of the Annual Review of Linguistics.

Rapidly improving AI has left governments, scientists and consumers alike wondering how best to harness its abilities and guard against its misuse, including the deepfakes now featuring in scams and propaganda. International leaders agreed to work together to guide the technology at the UK’s AI Safety Summit in November — hoping to get regulations in place before computers grow smarter than people.

Wild weather

News reports of broken heat records are starting to sound like, well, broken records. But 2023 really was a standout: The planet had its hottest year on record. As of October, it was about 1.4 degrees Celsius warmer than the 1850–1900 average, topping the previous greatest above-average heat bumps of about 1.3 degrees C in both 2020 and 2016.

This extreme heat of 2023 resulted from both long-term climate change trends and the year’s El Niño, a natural climate pattern that, overall, tends to make the world warmer. This was the hottest summer since recordkeeping began in 1880, and September was by far the most weirdly warm month ever seen. These trends have been shown to play a role in much of 2023’s wild and destructive weather, from Canada’s wildfires to Libya’s floods. Researchers suspect that the planet will hit a long-term average of 1.5 degrees C warming — a commonly quoted target for maximum warming — sometime in the early 2030s.

“Climate change is no longer about our grandchildren or polar bears — it is here, and now affecting everyone, everywhere on the planet, but especially devastating for the poor,” says Diana Ürge-Vorsatz, an environmental scientist and climate expert at Central European University and vice-chair of the Intergovernmental Panel on Climate Change. Ürge-Vorsatz co-penned an editorial calling for action against environmental crises in 2022’s volume of the Annual Review of Environment and Resources, for which she is a committee member.

Everything electric to end emissions

In December, delegates at the United Nations climate change convention discussed the first official inventory of our actions to combat global warming. The “global stocktake” concluded that while the world is making some progress and it will be possible to reach the Paris goal of limiting global warming to 2 degrees Celsius, leaders are going to have to accelerate action to get there.

For now, fossil fuel production remains too high for climate targets. But a Climate Analytics report says that there’s a 70 percent chance that greenhouse gas emissions will fall in 2024, making 2023 the “peak” year. Of course, getting away from fossil fuels means ramping up alternative energy sources. Renewables are soaring — particularly solar, and particularly in China. “Prices fell and penetration increased exceeding all projections,” says Ürge-Vorsatz of renewables. “In the first half of 2023, several countries have produced over three-quarters of their electricity from weather-dependent renewable forms of energy — still often deemed impossible by many experts.” At the December UN meeting, nations pledged to triple the planet’s renewable energy capacity by 2030.

New batteries in development will also help — 2023 saw a lab breakthrough in developing “lithium air” batteries. Meanwhile, researchers note some signs of hope that nuclear fusion might one day be feasible. The National Ignition Facility, an experimental laser-based fusion device at Lawrence Livermore National Laboratory in California, has produced slightly more energy than it used a total of four times since December 2022.

Fancy feast

As the world’s population grows, the quest continues for alternative high-protein foods that might mimic the sensory pleasures of meat without the attendant environmental problems from deforestation, greenhouse gas emissions and more. One option now on US plates is lab-grown meat, which was approved by regulators in June 2023, making the United States the second country to move “cellular meat” to market. Meanwhile, companies are also pursuing ever-better ways to make high-protein foods out of everything from insects to filamentous fungi to microbes that can convert air and hydrogen into edible food.

It’s exciting to see lab-grown meat finally reach the market, says Julian McClements, a food scientist at the University of Massachusetts Amherst and editor of the Annual Review of Food Science and Technology, who has written about next-generation plant-based foods. Scaling up that tech, he says, “has potential to create a more healthy, sustainable and ethical food supply.” At the same time, many nutrition experts are raising the alarm about ultraprocessed foods, and foods packed with sugars, salts and fats to increase desirability. Another more sustainable and healthier option to the world’s current diet would be to just eat more plants.

Body maps

Efforts to better understand the human body in health and disease got a boost this year with several projects aiming to map out vital organs and improve diversity in medical datasets. “It’s really an exciting time,” says Sarah Teichmann, co-lead of the Human Cell Atlas initiative and a member of the Annual Review of Genomics and Human Genetics editorial committee.

In June, researchers unveiled a comprehensive atlas of the lung, compiled from studies of 2.4 million cells in 486 people and highlighting cellular features common in cancer and Covid-19. In October, the largest-yet brain atlas was released, including more than 3,000 cell types, some of them new to science. Researchers are also expanding efforts to sequence and study the genomes of ever more people on this planet, hoping to shift medical datasets away from a current, common bias toward men of European descent. In October, a plan was launched to create the largest-yet database of genomes from people of African ancestry. All these efforts “could help lead to global democratization of health care in the future,” says Teichmann.

Ocean waves

For the oceans in 2023, “it was the best of times, it was the worst of times,” says Nancy Knowlton, a marine biologist with the Smithsonian National Museum of Natural History in Washington, DC, who wrote about reasons to be optimistic about ocean health in the 2021 Annual Review of Marine Science. On one hand, beleaguered global oceans hit a record high temperature in April and in August (near the tail end of the summer season for the global south and north, respectively), with “seas as hot as a hot tub,” says Knowlton. On the other hand, she says, 2023 saw “major steps being taken to reverse the trajectory of ocean decline.”

That includes a High Seas Treaty, agreed upon in March after years of effort, to provide more oversight of international waters. The treaty carves out ways to share benefits from genetic resources dug from the deep, and to create marine protected areas far from any national shores. Meanwhile, progress was made on a separate treaty aimed at eliminating plastic pollution — including the single-use plastics that plague marine environments. That treaty, due in 2024, might cap plastic production, better regulate recycling and promote more sustainable, healthier materials — like bioplastics or novel uses of wood.

Insect invaders

The insects in the spotlight this year were bedbugs, which ravaged first Paris (during Fashion Week, no less) and then Asia. But buggy concerns go far beyond this; a raft of far more damaging pests are also on the move, devastating crops and forests around the world. In September, a report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) reported that alien invasives, including insects, are a major factor in 60 percent of species extinctions. But while pests are spreading and making pests of themselves, there’s a parallel problem of insect decline (sometimes called the “insect apocalypse”), though numbers are still scant to document the collapse among our planet’s 5.5 million species of insects.

“Insects are not optional; they are the little things that run the world and if they were to disappear, humans would last but a few months,” says University of Delaware entomologist Doug Tallamy (read his 2023 interview with Knowable). Researchers are investigating new angles for insect conservation, including using genomics to track and assist the creatures’ ability to adapt.

Transplant tech

Lab advances are promising hope for people in need of organ transplants. This year, medical researchers for the first time managed to transplant previously frozen organs: In a landmark study published in June, rats successfully received kidneys that had been cryogenically frozen for 100 days. Researchers also made great strides in exploring medical use of organs from animals: Last year, a 57-year-old man with terminal heart illness survived for two months after receiving a pig heart. In 2023, researchers reported that a monkey survived an amazing two years with a pig kidney, thanks in part to genetic modification.

“Organ transplantation is close to my heart, as some family members have been recipients of kidney transplants,” says Edgar Arriaga, a member of the Annual Review of Analytical Chemistry editorial committee who applies chemistry and engineering to biomedical challenges. The new developments “shine renewed optimism onto many people whose only hope for having a normal life is a functional organ.”

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Reaching for stars

India became the fourth country to successfully put a lander on the Moon, to great fanfare. And NASA announced its intended crew for the next planned trip to the Moon (which will be in 2024 at the earliest). The four-person crew includes the first woman, the first person of color and the first non-American to head to the Moon.

Meanwhile, researchers looking far beyond the Moon to the stars now have a better tool in their toolkit: code that, finally, treats stars as the somewhat flattened, rotating, evolving balls that they are, rather than assuming they are perfect spheres. “At long last, this paper comes up with better models,” says Conny Aerts, an astrophysicist at KU Leuven in Belgium and a member of the Annual Review of Astronomy and Astrophysics editorial committee. “This is a remarkable achievement of major importance for astrophysics, because almost everyone in our field relies on stellar models.”

Fighting fat

The World Obesity Federation’s 2023 atlas predicts that more than half of the global population will be obese or overweight by 2035 — but new, effective drugs are emerging based on a better understanding of the hormones that control body weight. Many previous weight loss drugs targeted neurotransmitters such as norepinephrine to hit satiety and hunger centers in the brain. A new strategy instead targets the gut hormone GLP-1 (glucagon-like peptide 1), with a swath of benefits ranging from appetite suppression to blood sugar control.

The GLP-1-targeting drug Wegovy, approved in 2021, has proved wildly popular for weight loss, and this year a study showed that it could address heart problems in some patients, too. In November, a competitor, Zepbound, was also approved for weight loss in the United States. These developments are expected to lower the price on these expensive, injectable drugs. “This is truly an exciting and propitious time to be caring for individuals with the disease of obesity,” write endocrinologists Ania Jastreboff and Robert Kushner in an article tackling the subject in the Annual Review of Medicine.

Gene editing

In November, the UK medicines regulatory agency became the first in the world to approve a therapy that uses CRISPR gene editing — a revolutionary biotechnology that snips at DNA like a molecular scalpel. The United States followed suit in December. The treatment, called Casgevy, helps people with conditions caused by defective hemoglobin production or function, including sickle cell disease. The therapy is started by taking blood-producing cells out of the bone marrow of patients. The cells are genetically altered in the lab so that they produce fetal rather than adult hemoglobin, then infused back into the patient.

“The CRISPR revolution is the fastest advance in biomedicine I have seen,” says Donald Kohn, a medical geneticist at UCLA and coauthor of a recent overview of gene therapy in the Annual Review of Medicine. “This approval is just the first of many gene medicines to come.” CRISPR therapies are also being developed to tackle cancers, blindness, HIV, diabetes and more.