William Ripple, a distinguished professor in the Oregon State University College of Forestry, and former OSU postdoctoral researcher Christopher Wolf are the lead authors of the report, and 10 other U.S. and global scientists are co-authors.

“Without actions that address the root problem of humanity taking more from the Earth than it can safely give, we’re on our way to the potential collapse of natural and socioeconomic systems and a world with unbearable heat and shortages of food and freshwater,” Wolf said.

Published in BioScience, “The 2023 State of the climate report: Entering uncharted territory” notes that 20 of 35 planetary vital signs the authors use to track climate change are at record extremes.

The authors share new data illustrating that many climate-related records were broken by “enormous margins” in 2023, particularly those relating to ocean temperatures and sea ice. They also note an extraordinary Canadian wildfire season that produced unprecedented carbon dioxide emissions.

The report follows by four years the “World Scientists’ Warning of a Climate Emergency” published by Ripple and collaborators in BioScience and co-signed by more than 15,000 scientists in 161 countries.

“Life on our planet is clearly under siege,” Ripple said. “The statistical trends show deeply alarming patterns of climate-related variables and disasters. We also found little progress to report as far as humanity combating climate change.”

Among the key numbers in the report:

• Fossil fuel subsidies — actions by governments that artificially lower the cost of energy production, raise the price received by producers or lower the price paid by consumers — roughly doubled between 2021 and 2022, from $531 billion to just over $1 trillion.
• Already this year wildfires in Canada have pumped more than 1 gigaton of carbon dioxide into the atmosphere, greater than Canada’s total 2021 greenhouse gas emissions of 0.67 gigatons.
• In 2023, there have already been 38 days with global average temperatures more than 1.5 degrees Celsius above pre-industrial levels. Until this year, such days were a rarity, the authors note.
• The highest average Earth surface temperature ever recorded came this past July, and there’s reason to believe it was the highest surface temperature the planet has seen in the last 100,000 years.

“As scientists, we are hugely troubled by the sudden increases in the frequency and severity of climate-related disasters,” said Wolf, now a scientist with Corvallis-based Terrestrial Ecosystems Research Associates. “The frequency and severity of those disasters might be outpacing rising temperatures. By the end of the 21st century, as many as 3 to 6 billion people may find themselves outside the Earth’s livable regions, meaning they will be encountering severe heat, limited food availability and elevated mortality rates.”

The authors say policies are needed that take aim at the underlying issue of “ecological overshoot.” When human demand on the Earth’s resources is too large, the result in an array of environmental crises, including biodiversity decline. As long as humanity continues to put extreme pressure on the planet, any strategy that focuses only on carbon or climate will simply redistribute the pressure, they note.

“Our goal is to communicate climate facts and make policy recommendations,” Ripple said. “It is a moral duty of scientists and our institutions to alert humanity of any potential existential threat and to show leadership in taking action.”

The authors urge transitioning to a global economy that prioritizes human well-being and curtails overconsumption and excessive emissions by the rich. Specific recommendations include phasing out fossil fuel subsidies, transitioning toward plant-based diets, scaling up forest protection efforts and adopting international coal elimination and fossil fuel non-proliferation treaties.

They stress that all climate-related actions must be grounded in equity and social justice, noting that extreme weather and other climate impacts are being disproportionately felt by the poorest people, who have contributed the least to climate change.

The scientists, including Penn State faculty Nelson Dzade, reported in the journal Nature Energy their new method for creating more durable perovskite solar cells that still achieve a high efficiency of 21.59% conversion of sunlight to electricity.

Perovskites are promising solar technology because the cells can be manufactured at room temperature using less energy than traditional silicon materials, making them more affordable and more sustainable to produce, according to the Dzade, assistant professor of energy and mineral engineering in the John and Willie Leone Family Department of Energy and Mineral Engineering and co-author of the study. But the leading candidates used to make these devices, hybrid organic-inorganic metal halides, contain organic components that are susceptible to moisture, oxygen and heat, and exposure to real-world conditions can lead to rapid performance degradation, the scientists said.

One solution involves turning instead to all-inorganic perovskite materials like cesium lead iodide, which has good electrical properties and a superior tolerance to environmental factors. However, this material is polymorphic, meaning it has multiple phases with different crystalline structures. Two of the photoactive phases are good for solar cells, but they can easily convert to an undesirable non-photoactive phase at room temperature, which introduces defects and degrades the efficiency of the solar cell, the scientists said.

The scientists combined the two photoactive polymorphs of cesium lead iodide to form a phase-heterojunction — which can suppress the transformation to the undesirable phase, the scientists said. Heterojunctions are formed by stacking different semiconductor materials, like layers in a solar cell, with dissimilar optoelectronic properties. These junctions in solar devices can be tailored to help absorb more energy from the sun and convert it into electricity more efficiently.

“The beautiful thing about this work is that it shows the fabrication of phase heterojunction solar cells by utilizing two polymorphs of the same material is the way to go,” Dzade said. “It improves material stability and prevents interconversion between the two phases. The formation of a coherent interface between the two phases allows electrons to flow easily across the device, leading to enhanced power conversion efficiency. That is what we demonstrated in this piece of work.”

The researchers fabricated a device that achieved a 21.59% power conversion efficiency, among the highest reported for this type of approach, and excellent stability. The devices maintained more than 90% of the initial efficiency after 200?hours of storage under ambient conditions, Dzade said.

“When scaled from a laboratory to a real-world solar module, our design exhibited a power conversion efficiency of 18.43% for a solar cell area of more than 7 square inches (18.08 centimeters squared),” Dzade said. “These initial results highlight the potential of our approach for developing ultra-large perovskite solar cell modules and reliably assessing their stability.”

Dzade modeled the structure and electronic properties of the heterojunction at the atomic scale and found that bringing the two photoactive phases together created a stable and coherent interface structure, which promotes efficient charge separation and transfer — desirable properties for achieving high efficiency solar devices.

Dzade’s colleagues at Chonnam University in South Korea developed the unique dual deposition method for fabricating the device — depositing one phase with a hot-air technique and the other with triple-source thermal evaporation. Adding small amounts of molecular and organic additives during the deposition process further improved the electrical properties, efficiency and stability of the device, said Sawanta S. Mali, a research professor at Chonnam University in South Korea and lead author on the paper.

“We believe the dual deposition technique we developed in this work will have important implications for fabricating highly efficient and stable perovskite solar cells moving forward,” said Nelson Dzade, assistant professor of energy and mineral engineering in the John and Willie Leone Family Department of Energy and Mineral Engineering and co-author of the study.

The researchers said the dual deposition technique could pave the way for the development of additional solar cells based on all inorganic perovskites or other halide perovskite compositions. In addition to extending the technique to different compositions, future work will involve making the current phase-heterojunction cells more durable in real-world conditions and scaling them to the size of traditional solar panels, the researchers said.

“With this approach, we believe it should be possible in the near future to shoot the efficiency of this material past 25%,” Dzade said. “And once we do that, commercialization becomes very close.”

Also contributing were Chang Kook Hong, professor, and Jyoti Patil, research professor, at Chonnam National University, South Korea; Yu-Wu Zhong, professor, and Jiang-Yang Shao, researcher, at the Institute of Chemistry, Chinese Academy of Sciences; and Sachin Rondiya, assistant professor, Indian Institute of Science.

The National Research Foundation of Korea supported this work. Computer simulations were performed on the Roar Supercomputer in the Institute for Computational and Data Sciences at Penn State.

The first study of its kind followed a satellite over six years, observing how the panels generated power and weathered solar radiation over 30,000 orbits.

The findings could pave the way for commercially viable solar farms in space.

Professor Craig Underwood, Emeritus Professor of Spacecraft Engineering at the Surrey Space Centre at the University of Surrey, said:

“We are very pleased that a mission designed to last one year is still working after six. These detailed data show the panels have resisted radiation and their thin-film structure has not deteriorated in the harsh thermal and vacuum conditions of space.

“This ultra-low mass solar cell technology could lead to large, low-cost solar power stations deployed in space, bringing clean energy back to Earth — and now we have the first evidence that the technology works reliably in orbit.”

Researchers from the University of Swansea’s Centre for Solar Energy Research developed new solar cells from cadmium telluride. The panels cover a larger area, are more lightweight, and provide far greater power than current technology — as well as being relatively cheap to manufacture.

Scientists from the University of Surrey designed instruments that measured their performance in orbit. The satellite itself was designed and built at the Surrey Space Centre in partnership with a team of trainee engineers from the Algerian Space Agency (ASAL).

Although the cells’ power output became less efficient over time, researchers believe their findings prove that solar power satellites work and could be commercially viable.

Dr Dan Lamb from the University of Swansea said:

“The successful flight test of this novel thin film solar cell payload has leveraged funding opportunities to further develop this technology.”

“Large area solar arrays for space applications are a rapidly expanding market and demonstrations such as this help to build on the UK’s world class reputations for space technology.”