The research was published September 10 in Nature and forms part of the latest Worldwide Fund for Nature (WWF) Living Planet Report. The work was led by the International Institute for Applied Systems Analysis (IIASA), a research institute based in Austria.

“This important paper adds further evidence that food and environmental security are not incompatible,” said Fabrice DeClerck, a co-author and senior scientist at the Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT), who co-authored 2019’s EAT-Lancet report that outlined food system transitions to feed 10 billion people sustainably by 2050.

In a novel approach to explore future terrestrial biodiversity trends as affected by habitat conversion, the researchers built an ensemble of models to better understand possible future scenarios, much in the same way the International Panel on Climate Change (IPCC) creates future climate projections. They explore different assumptions — conservation and restoration efforts, and the impact of more sustainable food production and consumption practices — to build a timeline for a reversal in biodiversity loss.

“We wanted to assess in a robust manner whether it might be feasible to bend the curve of declining terrestrial biodiversity due to current and future land use, while avoiding jeopardizing our chances to achieve other Sustainable Development Goals (SDGs),” said David Leclère, the lead author and IIASA researcher. “If this were indeed possible, we also wanted to explore how to get there and, more specifically, what type of actions would be required, and how combining various types of actions might reduce trade-offs among objectives.”

The study comes at a relevant time for international discussions related to climate, conservation and food systems, including the United Nations Convention on Biological Diversity, which is taking stock of its Strategic Plan for Biodiversity 2011-2020.

The research was also featured in the 5th Global Biodiversity Outlook, released this week.

“We found that apart from increased conservation efforts, the most important actions to revert the loss of biodiversity are all related to how we manage the food system,” said Mario Herrero, the chief research scientist for agriculture and food at CSIRO, Australia’s national research agency. “Key transitions towards healthy and sustainable diets, renewed waste reduction efforts and increases in productivity will help enormously restore ecosystems. These are central elements where we need investment and action and are an integral part of the forthcoming World Food Summit.”

How much loss is already locked in?

Even under a best-case scenario, ongoing land conversion will drive further biodiversity loss before the curve starts bending. At least a third of the projected losses in the coming years are unlikely to be avoided under any scenario. Potential biodiversity losses were found to be highest in the regions richest in biodiversity, including sub-Saharan Africa (SSA), South Asia, Southeast Asia, the Caribbean and Latin America.

The study’s baseline projections for biodiversity loss — which include global and local extinctions and reductions in viable population levels for plants and animals — will be driven by the loss of about 5.3 million km2 of unmanaged forest and natural vegetation by 2050. To have a chance at reversing biodiversity loss — or bending the biodiversity curve towards restoration — about 9.8 million km2 must be restored by 2050. This implies a significant increase to the Bonn Challenge, an international agreement to bring 3.5 million km2 into restoration by 2030.

While study does not factor in the impact of climate change, the authors discuss climate’s increasing role in biodiversity loss, writing:

“Land-use change is currently the largest single threat to biodiversity, but other threats will increase in importance in the future, in particular climate change.”

Additionally, the “Integrated Action Portfolio” proposed by the researchers to address biodiversity loss implies doubling crop yields in SSA, which will be no easy feat. “While significant yield gaps prevailing in this region might offer opportunities, closing the yield gap in a sustainable manner will require investments and innovative policies, and might be complicated by climate change,” they wrote.

“We need to adopt a zero land conversion approach,” said DeClerck. “We need to realize that doubling productivity in SSA amongst others is a core contribution to the biodiversity and food security challenge, combined with producing the foods that contribute to, rather than detract from public health.”

While a rapidly shifting climate is hurting biodiversity, Climate will also play a big role in the sustainable intensification of agriculture, especially in places like sub-Saharan Africa where agricultural production will need to increase considerably in order to meet land conservation goals.

Terrestrial habitats will need to be better protected, the researchers argue. Even if current global agreements to protect 17 percent of land by 2020 are more than doubled to 40 percent and include biodiversity hotspots, about half of biodiversity losses projected under the study’s baseline scenario will not be avoided.

But the effectiveness of protected areas is declining as pressures on those areas are growing.

The report is not all bad news. Complementing research published in the past couple of years, the team found that integrated efforts that target habitat conservation, improved production practices and significant shifts towards healthy and less wasteful diets enable reversing the loss of biodiversity. These efforts are similarly necessary to achieve climate security and are not incompatible with global food security targets. Urgent action is needed this decade, however, to have any chance of transitioning to a net-nature positive scenario.

Tesserae are tectonically deformed regions on the surface of Venus that are often more elevated than the surrounding landscape. They comprise about 7% of the planet’s surface, and are always the oldest feature in their immediate surroundings, dating to about 750 million years old. In a new study appearing in Geology, the researchers show that a significant portion of the tesserae have striations consistent with layering.

“There are generally two explanations for tesserae — either they are made of volcanic rocks, or they are counterparts of Earth’s continental crust,” says Paul Byrne, associate professor of planetary science at North Carolina State University and lead author of the study. “But the layering we find on some of the tessera isn’t consistent with the continental crust explanation.”

The team analyzed images of Venus’ surface from NASA’s 1989 Magellan mission, which used radar to image 98% of the planet through its dense atmosphere. While researchers have studied the tesserae for decades, prior to this work the layering of the tesserae hasn’t been recognized as widespread. And according to Byrne, that layering would not be possible if the tesserae were portions of continental crust.

“Continental crust is composed mainly of granite, an igneous rock formed when tectonic plates move and water is subducted from the surface,” Byrne says. “But granite doesn’t form layers. If there’s continental crust on Venus, then it’s below the layered rocks we see.

“Aside from volcanic activity, the other way to make layered rock is through sedimentary deposits, like sandstone or limestone. There isn’t a single place today on Venus where these kinds of rocks could form. The surface of Venus is as hot as a self-cleaning oven and the pressure is equivalent to being 900 meters (about 985 yards) underwater. So the evidence right now points to some portions of the tesserae being made up of layered volcanic rock, similar to that found on Earth.”

Byrne hopes that the work will help to shed light on more of Venus’ complicated geological history.

“While the data we have now point to volcanic origins for the tesserae, if we were one day able to sample them and find that they are sedimentary rocks, then they would have had to have formed when the climate was very different — perhaps even Earth-like,” Byrne says.

“Venus today is hellish, but we don’t know if it was always like this. Was it once like Earth but suffered catastrophic volcanic eruptions that ruined the planet? Right now we cannot say for certain, but the fact of the layering in the tesserae narrows down the potential origins of this rock.”

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The results point to a greater range of possibilities, from ice sheet change that decreases sea level by 3.1 in (7.8 cm), to increasing it by 12 in (30 cm) by 2100, with different climate scenarios and climate model inputs. The regional projections show the greatest loss in West Antarctica, responsible for up to 7.1 in (18 cm) of sea level rise by 2100 in the warmest conditions, according to the research.

“The Amundsen Sea region in West Antarctica and Wilkes Land in East Antarctica are the two regions most sensitive to warming ocean temperatures and changing currents, and will continue to lose large amounts of ice,” said He?le?ne Seroussi, an ice scientist at NASA’s Jet Propulsion Laboratory in Southern California. Seroussi led the Antarctic ice sheet modeling in the ISMIP6 effort. “With these new results, we can focus our efforts in the correct direction and know what needs to be worked on to continue improving the projections.”

Different groups within the ISMIP6 community are working on various aspects of the ice sheet modeling effort. All are designed to better understand why the ice sheets are changing and to improve estimates of how much ice sheets will contribute to sea level rise. Other recent ISMIP6 studies include:

• How historical conditions and warming ocean temperatures that melt floating ice shelves from below play a significant role in Antarctic ice loss? (Reese et al, 2020)
• How sudden and sustained collapse of the floating ice shelves impact the Antarctic ice sheet as a whole? (Sun et al., 2020)
• How to convert large scale climate output into local conditions that ice sheet models can use? (Barthel et al, 2020; Slater et al; 2019, 2020; Nowicki et al., 2020, and Jourdain et al., 2020)

“It took over six years of workshops and teleconferences with scientists from around the world working on ice sheet, atmosphere, and ocean modeling to build a community that was able to ultimately improve our sea level rise projections,” Nowicki said. “The reason it worked is because the polar community is small, and we’re all very keen on getting this problem of future sea level right. We need to know these numbers.”

The new results will help inform the Sixth IPCC report scheduled for release in 2022.

Results from this effort are in line with projections in the Intergovernmental Panel on Climate Change’s (IPCC) 2019 Special Report on Oceans and the Cryosphere. Meltwater from ice sheets contribute about a third of the total global sea level rise. The IPCC report projected that Greenland would contribute 3.1 to 10.6 inches (8 to 27 cm) to global sea level rise between 2000-2100 and Antarctica could contribute 1.2 to 11 inches (3 to 28 cm).

These new results, published this week in a special issue of the journal The Cryosphere, come from the Ice Sheet Model Intercomparison Project (ISMIP6) led by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The study is one of many efforts scientists are involved in to project the impact of a warming climate on melting ice sheets, understand its causes and track sea level rise.

“One of the biggest uncertainties when it comes to how much sea level will rise in the future is how much the ice sheets will contribute,” said project leader and ice scientist Sophie Nowicki, now at the University at Buffalo, and formerly at NASA Goddard. “And how much the ice sheets contribute is really dependent on what the climate will do.”

“The strength of ISMIP6 was to bring together most of the ice sheet modeling groups around the world, and then connect with other communities of ocean and atmospheric modelers as well, to better understand what could happen to the ice sheets,” said Heiko Goelzer, a scientist from Utrecht University in the Netherlands, now at NORCE Norwegian Research Centre in Norway. Goelzer led the Greenland ice sheet ISMIP6 effort.

With warming air temperatures melting the surface of the ice sheet, and warming ocean temperatures causing ocean-terminating glaciers to retreat, Greenland’s ice sheet is a significant contributor to sea level rise. The ISMIP6 team investigated two different scenarios the IPCC has set for future climate to predict sea level rise between 2015 and 2100: one with carbon emissions increasing rapidly and another with lower emissions.

In the high emissions scenario, they found that the Greenland ice sheet would lead to an additional global sea level rise of about 3.5 inches (9 cm) by 2100. In the lower emissions scenario, the loss from the ice sheet would raise global sea level by about 1.3 inches (3 cm). This is beyond what is already destined to be lost from the ice sheet due to warming temperatures between pre-industrial times and now; previous studies have estimated that ‘locked in’ contribution to global sea level rise by 2100 to be about a quarter-inch (6 millimeters) for the Greenland ice sheet.

The ISMIP6 team also analyzed the Antarctic ice sheet to understand how much ice melt from future climate change would add to sea level rise, beyond what recent warming temperatures have already put in motion. Ice loss from the Antarctic ice sheet is more difficult to predict: In the west, warm ocean currents erode the bottom of large floating ice shelves, causing loss; while the vast East Antarctic ice sheet can gain mass, as warmer temperatures cause increased snowfall.

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Materials provided by NASA/Goddard Space Flight Center. Original written by Kate Ramsayer. Note: Content may be edited for style and length.