🌍 Vegetation changes significantly amplified cooling, driving grassland expansion, cloud seeding in China

Welcome to the 26th issue of Sustainability by Interesting Engineering. 

Last month, scientists determined that the 2023-2024 record-breaking global sea surface temperature anomaly was identified as an exceedingly rare event in a new Nature study. They estimate it to be a 1-in-500-year event, associated with the current global warming trajectory.

In the latest news, scientists have discovered that during the Miocene epoch, declining carbon dioxide (CO2) caused widespread cooling and drying. Although other factors, such as paleogeographic and vegetation changes, also played significant roles in this climate transition. This contributed to the expansion of grasslands.

Also, scientists in China conducted a weather modification experiment in the dry region of Xinjiang with the aim of driving rainfall. The project team, led by Li Bin, a senior engineer with the China Meteorological Administration (CMA), stated that a fleet of cloud seeding drones increased rainfall by over four percent across more than 8,000 sq km (3,089 sq miles) in a day.

This is equivalent to 30 filled Olympic-sized swimming pools, each 6.5 feet deep—using just 2.2 pounds of silver iodide, a common cloud-seeding compound. This amount of powder, six times denser than water, is small enough to fit in a travel mug.

Lastly, California-based photovoltaic systems provider Sunrun has announced that it has completed turning thousands of homes into the US’s largest virtual power plant. The firm’s CalReady system links domestic battery storage with solar panels to help keep the lights and AC on throughout the year. The setup should provide around 375 megawatts (MW) of backup power to power around 280,000 homes, the equivalent of all of Ventura County.

Did a friend forward this e-mail to you?

IE₊ SUPPORT INTERESTING ENGINEERING
_{Invest In Science And Engineering}

Subscribe to IE+: Join us as we delve into exclusive weekly content on sustainable technology. You now have the opportunity to join our eco-conscious community, gaining access to top stories on sustainability in STEM, along with recommendations and tips to embark on your own sustainable journey—all ad-free.

NEWS BULLETIN

🚁 Drones spread a cup of cloud seed in China, causing 30 swimming pools of rain 
A weather modification experiment in China’s Xinjiang, which involved dispersing 2.2 pounds of silver iodide into the atmosphere, has produced more than 18.5 million gallons of rain, equaling an increase of 4%.

🐋 Whale urine helps fertilize sea by dispersing nutrients, critical for marine life 
A recent study suggests that baleen whale urine boosts phytoplankton activity in the sea, contributing to the removal of an estimated 18,180 tons of carbon from the atmosphere each year.

🏠 California firm turns 56,000 homes into US’ largest virtual power plant
Sunrun’s CalReady system, which operates on 75,000 home batteries linked together, will provide 375 megawatts (MW) of backup power to power around 280,000 homes, equivalent to all of Ventura County.

🧊 Fingerprints of city-sized icebergs found off UK coast 
Icebergs as large as cities, potentially tens of kilometres wide, once roamed the coasts of the UK, according to scientists.

🇺🇸 Scientific societies to do climate assessment after Trump administration dismissed authors
Two groups joined forces for peer-reviewed research after key contributors to the Congress-mandated report were dismissed.

🌍 Race to tap Earth’s deep heat: How super-hot geothermal could power the post-carbon world
New microwave drills and shale-style fracking could unlock supercritical geothermal wells five to 20 km deep.

MUST-READ

🌿 Vegetation changes significantly amplified cooling, driving grassland expansion

According to a new study, changes in vegetation methods during the late Miocene period played a significant role in accelerating climate change. 

In an aim to achieve better comprehension of the major global climate shift during the Miocene epoch, researchers particularly investigated the role of vegetation feedbacks in driving this climate change. 

The Miocene epoch, spanning from approximately 23.03 to 5.333 million years ago, witnessed a global trend of cooling and drying that contributed to the expansion of grasslands. While the loss of carbon dioxide (CO2) contributed to the widespread cooling and drying, other factors, such as paleogeographic and vegetation changes, also played significant roles.

Tectonic shifts also made northern areas cooler and brought more rain to some regions like East Asia, East Africa, and South America. However, changes in vegetation had an even greater impact, especially making northern high latitudes much colder and altering rainfall in low and mid latitudes.

“In comparison, vegetation changes accelerated cooling at northern high latitudes (the maximum cooling exceeded 10 degrees Celsius) and modulated precipitation at low- and mid-latitude continents (the maximum decrease was close to 30 percent),” the study stated. 

The research also found that these plant-driven changes, by modifying surface reflectivity (albedo) and interacting with water vapor, clouds, and sea ice, amplified the cooling effect and altered precipitation patterns. In some regions, the change was even more significant than the decline in CO2 levels alone.

The study was led by Professor Ran Zhang from the Institute of Atmospheric Physics, Chinese Academy of Sciences. It was published on May 2, 2025, in the journal Science Advances.

OTHER IMPORTANT UPDATES

🌡️ Disastrous back-to-back heatwaves and droughts surge across Eurasia

☀️ Ultra-high efficiency achieved in silicon solar panels with new, smart nanostructural layer

🔋 26% efficient perovskite solar cell retains 98% performance after 2,100 hours

🇸🇪 The Swedish city fined for missing an environmental target

🛢️ Revealed: Forecasts of greenhouse gas emissions from fossil fuels soar in Trump’s first 100 days

⚡ Shocking twist: Electricity-making bacteria may power clean energy breakthroughs

🚗 Nickel breakthrough: EV batteries become 84% greener with new zero-carbon process

🌍 Act to shrink your carbon footprint

From April 28 to April 30, 2025, the 10th Our Ocean Conference (OOC) took place in Busan, South Korea. The “Our Ocean, Our Action” event centred on the theme of digital oceans. 

“The tenth Our Ocean Conference will primarily focus on the achievements and success stories over the past 10 years, while also establishing the future direction for international cooperation over the next decade,” stated Do-hyung Kang, Minister of the Ministry of Oceans and Fisheries of the Republic of Korea. “The conference is set to be a significant moment for international cooperation, providing a crucial foundation for our collective efforts towards a shared future.”

The conference organisers said that commitments were made by more than 60 different countries and organizations across six key ocean action areas: Ocean Climate Nexus, Marine Pollution, Marine Protected Area, Sustainable Blue Economy, Sustainable Fisheries, and Maritime Security.

These commitments collectively are valued at over $9.1 billion. The commitments were made across six key action areas:   

• 🌊 Ocean Climate Nexus: Addressing the link between the ocean and climate change, including initiatives for green shipping and nature-based solutions like restoring blue carbon ecosystems (nearly $150 million in finance for this area).   

• 🚯 Marine Pollution: With over 20 percent of the commitments addressing plastic pollution specifically, including new recycling programs, national plans, and education initiatives. Other pollution issues, like noise and wastewater, were also addressed.   

• 🛡️ Marine Protected Areas (MPAs): Over 45 commitments focused on identifying and assessing new MPA sites, expanding and improving the management of existing MPAs, and protecting key habitats.

• 🌐 Sustainable Blue Economy: This area garnered the highest single financial commitment of any action area – $4.5 billion – and the second-highest number of total commitments (59). Pledges aimed to support ocean entrepreneurship, develop blue economy frameworks, and enhance sustainable small-scale fisheries and aquaculture using digital technologies.   

• 🎣 Sustainable Fisheries: Commitments focused on promoting responsible fisheries management and combating illegal, unreported, and unregulated (IUU) fishing. South Korea, Ghana, and Cameroon notably endorsed the Global Charter for Fisheries Transparency.   

• 🚢 Maritime Security: Nearly 20 commitments were made to improve maritime security capacity and counter IUU fishing efforts globally, particularly in the Pacific and West Africa.