Coral adaptation faces limits under escalating global warming
Coral adaptation to rising ocean temperatures and marine heatwaves is unlikely to match the pace of climate change without significant reductions in global greenhouse gas emissions, according to a study published in Science.
Led by Dr. Liam Lachs from Newcastle University, the research highlights that coral heat tolerance via natural selection can adapt to some warming scenarios, but this is contingent on limiting global warming to the two-degree threshold established by the Paris Agreement.
Marine heatwaves are increasingly causing mass coral bleaching events, and their growing frequency poses a severe challenge. Using an eco-evolutionary simulation model, the study examined coral populations in Palau, incorporating biological and ecological data to simulate the impact of varying emissions scenarios.
Dr. Lachs noted: “Our study shows that scope for adaptation will likely be overwhelmed for moderate to high levels of warming.”
Co-author Prof. Peter Mumby from the University of Queensland emphasized the dire consequences of failing to meet global climate commitments: “Under such levels of warming, natural selection may be insufficient to ensure the survival of some of the more sensitive yet important coral species.” Strategic reductions in emissions and innovative coral reef management could mitigate these effects.
The findings stress the urgency of climate-smart management strategies, with co-author Dr. James Guest advocating for maximizing genetic adaptation and exploring emerging solutions like assisted evolution interventions. Dr. Lachs concluded, “If rapid climate action can be achieved, genetic adaptation could offset some of the projected loss of coral reef functioning and biodiversity over the 21st century.”
Journal Reference:
Liam Lachs et al. ‘Natural selection could determine whether Acropora corals persist under expected climate change’, Science eadl6480 (2024). DOI: 10.1126/science.adl6480
Article Source: Newcastle University
Harnessing agrifood value chains for climate-smart farming
A new paper in Science outlines how agrifood value chains (AVCs) can empower farmers to adopt climate-smart agricultural practices, addressing both mitigation and adaptation challenges.
Authored by experts from the International Food Policy Research Institute (IFPRI), the World Bank Group, and Michigan State University, the paper emphasizes the critical role of AVC structures and incentives in advancing sustainable farming.
The study advocates for utilizing AVCs, which link input providers to retailers, to distribute essential tools such as resource provision contracts and climate-resilient technologies. Johan Swinnen, one of the authors, remarked, “AVCs can drive farmers’ adoption of climate-smart practices through tools like resource provision contracts, technology transfer, and financial incentives.”
The study highlights that most current climate efforts focus on multinational corporations, neglecting the role of smaller enterprises, particularly in the Global South. Thomas Reardon underscored their potential: “Micro, small, and medium enterprises can unleash grassroots transformation by providing small farmers with essential inputs, training, credit, and logistics in support of climate-smart agriculture.”
The paper also proposes robust policy measures to strengthen AVCs, such as redirecting subsidies toward sustainability, de-risking investments, and fostering inclusive regulations.
Loraine Ronchi of the World Bank emphasized, “Agrifood value chains represent a significant, but still largely untapped opportunity to drive climate-smart agriculture and build sustainable food systems.”
Journal Reference:
Johan Swinnen, Loraine Ronchi, and Thomas Reardon, ‘Harness agrifood value chains to help farmers be climate smart’, Science 386, (6725) 974-977 (2024). DOI: 10.1126/science.adr6193
Article Source: International Food Policy Research Institute
Compound dry-hot events in China linked to human activities over 120 years
A century-long analysis published in Earth’s Future reveals a dramatic rise in compound dry-hot events in China, particularly over the last four decades. The study, led by Ruixin Duan and colleagues, highlights that these events – driven by temperature and precipitation changes – are increasingly influenced by human activities.
Between 1981 and 2020, the frequency of compound dry-hot events rose fourfold compared to the early 20th century, with temperature changes contributing more significantly (56%) than precipitation (23%). The study attributes this sharp increase primarily to human-induced climate change, with regional probabilities of such events rising by 7.9% to 31.6% due to anthropogenic influences.
The findings emphasize the heightened severity and prolonged impacts of compound events compared to single-variable extremes. “Our study utilizes long-term observational data to unveil the evolution of compound dry-hot events in China, with a particular focus on dissecting the extent of human contributions,” the researchers stated.
The study underscores the pressing need for mitigation measures to address the amplified risks posed by these events, which threaten water resources, agriculture, and ecosystems across China.
Journal Reference:
Ruixin Duan, Guohe Huang, Feng Wang, Chuyin Tian, Xinying Wu, ‘Observations Over a Century Underscore an Increasing Likelihood of Compound Dry-Hot Events in China’, Earth’s Future 12 (11), e2024EF004546 (2024). DOI: 10.1029/2024EF004546
Article Source: American Geophysical Union (AGU)
Featured image credit: Gerd Altmann | Pixabay
