New research by Arizona State University, the National Oceanic and Atmospheric Administration’s Pacific Islands Fisheries Science Center (PIFSC) and Bangor University in the U.K. indicates that mitigating both local land and sea-based human impacts, especially in terms of pollutants and over-fishing, provides coral reef ecosystems with the best opportunity to persist under climate change. Along some highly populated areas on the shorelines of Hawai’i, wastewater pollution and urban runoff combine with fishing pressures to put immense stress on coral reefs.

The paper, “Coral reefs benefit from reduced land-sea impacts under ocean warming,” published in the multidisciplinary science journal August 9.

“There is a very strong perception that declining reef health is mainly driven by climate change, which is true in the long term. However, what we are putting in our waters from our shores, as well as the amount of fishing we are doing, are huge drivers that are more immediately actionable,” said Greg Asner, senior author of the study and director of ASU’s Center for Global Discovery and Conservation Science. Asner said the 20-year time frame provided a unique opportunity to reflect on solution strategies.

These human-caused threats were most clearly demonstrated to have significant impact in 2015, when the Hawaiian Islands experienced the strongest marine heatwave on record over the past 120 years.

“The 2015 marine heatwave in Hawai’i was unprecedented: nothing comes close in well over a century of recorded temperature data,” said Jamison Gove, a research oceanographer with PIFSC and co-lead of the study. “As a consequence, many reefs in our study region experienced severe bleaching and extensive coral death. But to our surprise, we found that coral cover was unchanged at nearly 20% of reefs in our study. Which begs the question: why did some reefs fare better than others despite experiencing similarly extreme levels of heat stress?”

Local land-sea conditions were the difference: the reefs that had less coral loss from the heatwave were the same reefs with the lowest levels of land-based stressors and increased fish populations. Asner said land-sea relationships are an area that can be greatly affected by policy efforts.

“We are deeply embedded with county, state and federal governments and working to try to resolve these issues,” said Asner, also a senior global futures scientist with the Julie Ann Wrigley Global Futures Laboratory at ASU. “Each of these governments can tackle a different tier of the problem, from wastewater issues to overarching climate change. Some of these issues will take longer to mitigate but some can see positive change now — wastewater issues can sometimes come down to individual buildings and houses.”

Wastewater pollution contains a high concentration of nutrients, toxins and pathogens that are known to increase coral disease and decrease growth and reproduction. Asner said septic tanks and cesspools, both common in Hawai’i, can be especially harmful to coral reefs.

Gareth Williams, associate professor at Bangor University and co-lead of the study, said the long-term research done through this study supports the theory that the land-sea relationship is an especially important element in coral reef protection.

“Integrated land-sea management has been the guiding paradigm of coral reef conservation for decades, but the proof of its efficacy above managing land or sea in isolation has been wanting and difficult to test,” Williams said. “Through the 20-year data set of local human impacts and environmental factors, we are able to see that only by adopting coupled land-sea policy measures, alongside global reductions in greenhouse gas emissions, will coral reef ecosystems and the human communities they support have the best opportunity for persistence in our changing climate.”

The findings, published in Oryx, suggest that conservation educational activities should be evaluated carefully to make sure they are achieving the desired objectives.

With increasing urbanisation and advances in technology, children’s exposure to the natural world has decreased.

To respond to this, conservationists have promoted educational activities to increase children’s understanding and awareness of environmental issues, but new research shows that this doesn’t always translate to them changing their attitudes or encourage them to become more involved in protecting the environment.

In a study published in Oryx, researchers from the University of Bath worked with conservation non-profit Maio Biodiversity Foundation (FMB) in Maio, Cape Verde, to assess the impacts of environmental education on schoolchildren from the island.

The Cape Verde Islands, near the west coast of Africa, are powerhouses of evolution, home to an abundance of wildlife, including whales, turtles, sharks and shorebirds.

However, unsustainable practices such as turtle poaching, off-road excursions through protected areas, and large scale litter dumping threatens to put local wildlife at risk.

The researchers investigated the influence of a one-time classroom activity on children’s knowledge of local environmental issues, environmental attitudes and future aspirations.

The half-day activity, with 10 classes of 9-10-year-olds (4^th grade) across eight schools (around 140 children), was focussed on the large wetland habitat of the island that is home to a wide variety of wildlife, including the largest breeding population of plover shorebirds that are genetically unique to the island.

The researchers talked to the children about the different species found locally, the environmental issues that threatened the wildlife and used a game activity to show the complex ecosystem of the area, helping the children understand how all the different parts were connected.

They assessed the children’s conservation knowledge, and attitudes to science and the environment before and after the activities to see how it had changed.

They found that whilst the activity was successful in improving the children’s knowledge and awareness of environmental issues, it did not change their attitudes towards animals and other wildlife.

Romy Rice, PhD student at the Milner Centre for Evolution at the University of Bath, was first author on the paper.

She said: “There is a real need to reconnect society with nature — especially in places of rich biodiversity, like Maio. It is so important to raise awareness of how certain human activities can put the amazing wildlife on people’s doorstep at risk.”

“Educating schoolchildren about conservation increases eco-awareness among their parents too, so it could be a powerful tool to influence knowledge and positive attitudes towards the environment across generations.

“We were surprised that although the activities increased the children’s knowledge, it didn’t necessarily change their attitudes towards nature. In some cases it actually decreased their interest in science.

“This study shows the importance of evaluating activities — we shouldn’t assume that increasing knowledge will help solve environmental issues.

“Instead we must carefully plan and assess activities to make sure they are achieving the desired objectives.”

Herval Silva, Assistant for Sustainable Development at FMB and co-author on the study, said: “This project was great to see how children learn and how we can improve their learning, especially when it comes to their understanding of our island’s biodiversity and their appreciation of the local wildlife.

“Right now, these children are the future of conservation, so the more we understand how they feel towards the environment, the better we can go on to develop ways to protect it.”

Romy plans more research to assess whether field trips are more impactful than classroom activities, or whether it simply distracts them.

Romy Rice is funded by the Evolution Education Trust, a charitable trust that funds the use of evolutionary science in research, interventions, education and outreach.

Published today (Wednesday 9 August), AIMS’ Annual Summary Report on Coral Reef Condition for 2022/23 found that while some reefs continued to recover, their increased hard coral cover was offset by coral loss on other reefs. Most reefs underwent little change in coral cover.

This follows last year’s report, which saw the Northern and Central regions recording their highest amount of coral cover since AIMS began monitoring 37 years ago.

The pauses in recovery in the Northern and Central regions were due in part to the 2022 mass coral bleaching event. Low numbers of coral-eating crown-of-thorns starfish and a cyclone in January 2022 also contributed to coral loss in the Northern region. Continued crown-of-thorns starfish outbreaks and coral disease kept coral cover similar to last year’s levels in the Southern region, with bleaching playing less of a role.

AIMS Research Program Director Dr David Wachenfeld said that while continued recovery on some reefs was good news, the pause in recovery showed that even relatively milder mass bleaching events had consequences for the Reef.

“The 2022 coral bleaching event was not as severe as the 2016 or 2017 events but caused enough mortality to pause recent regional gains in hard coral cover. The heat stress during the bleaching event also likely had sub-lethal effects, including reductions in coral growth and reproduction,” Dr Wachenfeld said.

“Conditions were relatively mild over the 2023 summer with low levels of coral bleaching and no cyclones crossing the Reef. However, we are only one large scale disturbance away from a rapid reversal of recent recovery.

“The Reef remains a wonderful, complex and beautiful system, but it is at increased risk with climate change driving more frequent and severe bleaching events, putting increasing pressure on the ecosystem’s resilience.”

The Report found the following in average hard coral coverage for 2022/23:

• Northern region (north of Cooktown) — 35.7%, down from 36.5% last year;
• Central region (Cooktown to Proserpine) — 30.8%, down from 32.6%;
• Southern region (south of Proserpine) — 33.8%, down from 33.9%.

Reef slopes on the perimeters of 111 reefs were surveyed between August 2022 and May 2023 for the report under the AIMS Long Term Monitoring Program (LTMP) — a 37-year-long dataset which is the largest, longest and most comprehensive information source on the status of the Great Barrier Reef.

AIMS Long-Term Monitoring Program leader Dr Mike Emslie said recovery over the last few years has been driven primarily, but not exclusively, by fast-growing branching and plate corals, or Acropora. These important habitat builders are also vulnerable to disturbances such as cyclones, crown-of-thorns starfish and coral bleaching.

“Acropora are highly abundant, responsible for most of the ups and downs in hard coral cover, and have been going through a rapid growth phase in recent years. But other corals on the Reef have also contributed to this recovery,” he said.

Dr Emslie noted the increased frequency of mass coral bleaching events on the Great Barrier Reef with four occurring since 2016.

“The 2022 bleaching event was the first ever recorded during a La Niña year, which are usually characterised by cooler temperatures,” he said.

“If there were no disturbances, we would expect the recent increases in coral cover to continue this year. However, this pause indicates that a mass bleaching event, even if less severe, with low mortality, is still enough to put the brakes on this coral recovery.

“This means the Reef is still at risk of decline from more frequent disturbances. AIMS is working to understand the effect of this climatic instability through monitoring and research.”

Dr Wachenfeld added: “The best hope for the future of the Great Barrier Reef and all coral reefs globally requires reduction in greenhouse gas emissions to stabilise temperatures, best practice management of local pressures, and the development of interventions to help boost climate tolerance and resilience for coral reefs.”

BACKGROUND

The LTMP quantifies long term trends in the status of coral communities across the Great Barrier Reef.

Researchers use hard coral cover as one indicator of the condition of each reef, although there are many others. Percentage hard coral cover is estimated by trained scientists during manta tow surveys and is a metric which allows AIMS scientists to provide an overview of the Great Barrier Reef’s status and keep policy makers, managers and other scientists informed in a timely manner.

Manta tow surveys are an efficient way to survey large areas of reef. It is a standard method to assess percent hard coral cover, estimates of crown-of-thorns starfish, levels of coral bleaching, and fish and shark populations.

The LTMP also does detailed surveys on fixed sites on 73 reefs across the Great Barrier Reef. These data provide deeper insights into the corals, fishes and crown of thorns starfish at these sites, their abundance, their age and more detailed information about coral disease and bleaching. 3D images are taken of these reefs to assess reef complexity and their changing structures.

The AIMS monitoring team spent 120 days at sea during this survey period. They travelled 1016km around the perimeter of the 111 reefs they surveyed.

The AIMS LTMP team begin their new survey season in late August. Surveys will continue through the summer and conclude around May 2024.

The LTMP contributes to the Reef 2050 Integrated Monitoring and Reporting Program.

Arctic sea ice, an important component of the Earth system, is disappearing fast under climate warming. Summer sea ice is anticipated to vanish entirely within this century. To gain a deeper understanding of the climate dynamics in a world without Arctic sea ice, researchers have turned to analogues from the geological past.

“The Last Interglacial, between 129,000 and 115,000 years BP, is an interesting period to study because it is the last time in Earth’s history when global average temperatures were similar or perhaps higher than currently and sea levels were considerably higher, up to +6 to +9 m,” said Flor Vermassen, postdoctoral researcher at Stockholm University.

However, the extent of sea ice during this period has been intensely debated and there is no consensus, limiting understanding of this period and the ability of researchers to simulate it in climate models. To address this, a team of marine geology researchers from the Department of Marine Geological Sciences at Stockholm University analysed the microfossil content of an array of sediment cores from sites that today lie directly beneath the thickest parts of the modern Arctic ice pack. In these cores, they investigated the variability in the occurrence and composition of planktonic foraminifera, a type of free-floating, shell-building unicellular zooplankton that is sensitive to changes in oceanographic and environmental conditions.

The researchers found high abundances of the typically subpolar, Atlantic-water species Turborotalita quinqueloba, documenting a large-scale expansion of the species far into the central Arctic Ocean. The ecological preference of T. quinqueloba for predominantly ice-free, seasonally productive waters typically present in the Atlantic Ocean suggests that it was following similar conditions that had spread to the central Arctic Ocean. The absence of summer sea ice and increased influence of Atlantic currents in the Arctic domain during the Last Interglacial are analogous to ocean transformations being observed today in parts of the Arctic, and collectively referred to as ‘Atlantification’ of the Arctic Ocean.

“The finding that the Arctic Ocean was seasonally ice-free during the Last Interglacial is worrying because this period would have been only around 1.5°C above pre-industrial levels, comparable to the targets of the Paris Agreement. Yet the global sea level is estimated to have been several meters higher than at present,” said Flor Vermassen.

Hence, the researchers propose the Last Interglacial as the most recent and potentially most relevant geological epoch for investigating a seasonally ice-free Arctic Ocean, particularly if the objectives of the Paris Agreement are not exceeded.

“To fully comprehend the physical conditions and environment of this unfamiliar Arctic during the Last Interglacial, additional quantitative proxy reconstructions of sea-surface temperature and other water mass parameters are needed, along with targeted climate and oceanographic model studies of the same period,” said Flor Vermassen.

The UN’s International Maritime Association reported in 2020 that the shipping industry — the ships moving freight between the continents — accounts for 2.89% of annual global CO2 emissions. Between 1990 and 2020, shipping volumes “more than doubled,” according to Statista, and during the COVID-19 pandemic, shipping grew faster, at as much as 16.4% a year, according to the U.S. International Trade Commission. Meet Eric Leveridge, the Pacific Environment Lead at Ship It Zero, a nonprofit coalition of environmental, public health, and shipping experts. The organization reports that the shipping emissions of just 15 retail companies, including Home Depot, Lowe’s, Walmart, Amazon, and Target, are responsible for 12.7 million tons of CO2 and as much particulate pollution as the entire U.S. mining industry.

Eric also digs into recent news that Amazon reversed its Climate Pledge commitment that would have made half of its shipping emissions-free by 2030. As reported by Business Insider, Amazon’s reason was, “We realized that it no longer made sense to have a separate and more narrow Shipment Zero goal that applied to only one part of our business, so we’ve decided to eliminate it.” Ship It Zero called on Amazon to reinstate its 50% net-zero shipping goals.

Shipping has many routes to lower emissions, including the use of hydrogen- or ammonia-based fuels, augmenting engines with wind power, and the addition of emissions scrubbing technology that captures and sequesters carbon, sulfur oxide, and nitrous oxide emissions instead of letting them escape into the atmosphere. Eric joins us to explore the challenge of lowering retailers’ shipping-related emissions and tell us about Ship It Zero’s recommendations.

You can learn more at shipitzero.org, which features several helpful e-books for those who want to read up on shipping emissions and pollution.

Chenliang Wu, PhD, a postdoctoral researcher at Tulane University School of Science and Engineering, began this research by looking at the Mississippi River before adding other rivers on Earth and ancient riverbeds on Mars to the study.

The study specifically looks at river sinuosity, or how much rivers curve. The sinuosity of rivers changes over time, depending on the age of the river and environmental changes. Some of these changes include sediment and water supply and riverbank vegetation, all of which are affected by climate change. The study found that river sinuosity is related to the changes in how much water flows through the river. Rivers have different water levels depending on environmental factors, like precipitation levels.

The researchers looked at maps of the rivers on Earth over time by using historical data from as early as the fifth century and images from as early as 1939. They used data of 21 lowland meandering rivers. For the ancient riverbeds on Mars, they used previously identified ancient river channels from remote sensing data.

The ancient riverbeds on Mars, untouched by human influence, gave Wu and his team a system to test their hypotheses on how the river systems migrated and what their sinuosity looked like by the time they dried up. Their analysis is also a step toward understanding what the hydroclimate on Mars was like when there was still surface water.

“It really lays the foundation for more advanced topics,” Wu said, “like, were the environmental conditions suitable for life on Mars?”

After performing analysis on the rivers, the researchers separated them into two categories: variable-sinuosity and constant-sinuosity. The variable-sinuosity rivers never reached a steady state, meaning their sinuosities continue changing, and the constant sinuosity rivers did reach a steady state, meaning their average sinuosity remained relatively constant. Of the 21 Earth rivers studied, 13, including the Mississippi River, had variable sinuosity, while 8 had constant sinuosity.

Understanding what factors affect the sinuosity of rivers will give researchers and engineers insight into how to manage rivers in the future. It can help with river restoration, future infrastructure projects and flood management. This insight can be invaluable in attempts to mitigate the impacts of climate change.

As more extreme weather happens more frequently due to the effects of climate change, research like Wu’s will become even more important when it comes to protecting and helping populations who live near rivers. According to a 2019 study in the International Journal of Water Resources Development, half of the world’s population lives in river basins, all of whom could be affected by future floods from extreme weather events.

Known as the Maillard reaction after the French scientist who discovered it, the process converts small molecules of organic carbon into bigger molecules known as polymers. In the kitchen, it is used to create flavours and aromas out of sugars.

But a research team led by Professor Caroline Peacock at the University of Leeds argues that on the sea floor, the process has had a more fundamental effect, where it has helped to raise oxygen and reduce carbon dioxide levels in the atmosphere, to create the conditions for complex life forms to emerge and thrive on Earth.

Source of organic carbon

Organic carbon in the oceans mostly comes from microscopic living organisms. When those organisms die, they sink to the sea floor and are consumed by bacteria. That decay process uses oxygen and releases carbon dioxide into the ocean which eventually ends up in the atmosphere.

As a result of the Maillard reaction, the smaller molecules are converted into larger molecules. Those larger molecules are harder for microorganisms to breakdown and remain stored in the sediment for tens of thousands — if not millions — of years.

The scientists describe this as the “preservation of organic carbon.”

That long-term storage or preservation of organic carbon on the seabed had major consequences for conditions that developed on the surface of the Earth. It limited the release of carbon dioxide, allowing more oxygen to reach the Earth’s atmosphere and limited variation in the warming of the Earth’s land surface over the last 400 million years to an average of about five degrees Celsius.

‘Too slow to have any impact’

Dr Oliver Moore, first author in the study and a Research Fellow in Biogeochemistry in the School of Earth and Environment at Leeds, said: “It had been suggested back in the 1970’s that the Maillard reaction might occur in marine sediments, but the process was thought to be too slow to impact the conditions that exist on Earth.

“Our experiments have shown that in the presence of key elements, namely iron and manganese which are found in sea water, the rate of reaction is increased by tens of times.

“Over Earth’s long history, this may have helped create the conditions necessary for complex life to inhabit the Earth.”

As part of the study, the scientists modelled how much organic carbon has been locked into the seabed because of the Maillard reaction. They estimate it has resulted in around 4 million tonnes of organic carbon each year being locked into the seabed. That is the equivalent weight of around 50 London Tower Bridges.

To test their theory, the researchers looked at what happened to simple organic compounds when mixed with different forms of iron and manganese in the laboratory at 10 degrees Celsius, the temperature of the seabed.

Analysis revealed that the “chemical fingerprint” of the laboratory samples — which had undergone the Maillard reaction — matched those from sediment samples taken from seabed locations around the world.

That “fingerprint” analysis was conducted at the Diamond Light Source in Oxfordshire, the UK’s synchrotron which generates intense beams of light energy to reveal the atomic structure of samples.

Dr Burkhard Kaulich, Principal Beamline Scientist of the Scanning X-ray Microscopy beamline (I08-SXM) at Diamond Light Source, said: “Our advanced I08-SXM instrumentation with its high stability, energy and optical resolution was developed and optimised to help probe carbon chemistry and reactions which take place in environmental systems.

“We are very proud to have been able to contribute to a better understanding of the fundamental chemical processes involved in the creation of complex life forms and climate on Earth.”

Professor Peacock, from Leeds, said: “It’s immensely exciting to discover that reactive minerals such as those made from iron and manganese within the ocean have been instrumental in creating the stable conditions necessary for life to have evolved on Earth.”

The lessons learned from a better understanding of the Earth’s geochemical processes could be used to harness new approaches to tackling modern-day climate change.

Dr James Bradley, an environmental scientist at Queen Mary University of London and one of the authors of the paper, said: “Understanding the complex processes affecting the fate of organic carbon that is deposited on the seafloor is crucial to pinpointing how Earth’s climate changes in response to both natural processes and human activity, and helping humanity better manage climate change, since the application and long-term success of carbon capture technologies relies on carbon being locked away in stable forms rather than being transformed into carbon dioxide.”

The research found that 33% of NBS were what are known as green solutions. These can include urban green spaces such as parks, green roofs, and green walls that can provide cooling and shade, absorb rainfall, and improve air quality.

A significant proportion (31%) of NBS were hybrid solutions. These can include green roofs that incorporate solar panels or rainwater harvesting systems to capture and use rainwater.

Professor Prashant Kumar, Director of the Global Centre for Clean Air Research (GCARE) and corresponding author of the study, said:

“The good news is that we found a wealth of evidence of more communities successfully adopting nature-based solutions to not only deal with climate change and hazards but societal issues such as water and food security. What is very concerning is that we found a lack of evidence of authorities or organisations investing in nature-based solutions for vulnerable communities outside of Europe.”

The team from GCARE analysed the implementation of more than 500 NBS case studies from across the globe. They found more than 88% of them were supported by national policies, which ensured the financial viability of the NBS.

The most common use of NBS was to address water-based hazards such as floods and landslides. This accounted for 45% of all case studies.

The second most common type of hazard addressed by NBS was meteorological/climatological hazards like heatwaves and droughts, which accounted for around 30% of the case studies. Around 24% of the case studies were focused on environmental hazards like soil degradation and air pollution. Fire hazards were the least common type of hazard addressed by NBS, accounting for only around 1% of the case studies.

Professor Kumar commented:

“We believe that as much as 68% of the case studies we analysed addressed UN Sustainability goals for life on land, climate action and clean water. Imagine the impact these innovations could have if they were implemented in our most vulnerable communities.

“This is why we believe that knowledge transfer must be near the top of the agenda so we can all benefit from the transformational benefit of nature-based solutions.”

The study was supported by the EU project, OPERANDUM (Grant Agreement No: 776848) and published in the Science of the Total Environment journal.

The University of Surrey is a world-leading centre for excellence in sustainability — where our multi-disciplinary research connects society and technology to equip humanity with the tools to tackle climate change, clean our air, reduce the impacts of pollution on health and help us live better, more sustainable lives. The University is committed to improving its own resource efficiency on its estate and being a sector leader, aiming to be carbon neutral by 2030. A focus on research that makes a difference to the world has contributed to Surrey being ranked 55th in the world in the Times Higher Education (THE) University Impact Rankings 2022, which assesses more than 1,400 universities’ performance against the United Nations’ Sustainable Development Goals (SDGs).