Veille 2.1

An intense heat wave gripping South and South-East Asia since late March comes as no surprise to leading meteorologists who have been warning of steadily rising temperatures in the Indian Ocean.

An international team of scientists has warned against relying on nature providing straightforward 'early warning' indicators of a climate disaster, as new mathematical modeling shows new fascinating aspects of the complexity of the dynamics of climate. It suggests that the climate system could be more unpredictable than previously thought.

A long-term sea level dataset shows ocean surface heights continuing to rise at faster and faster rates over decades of observations. Global average sea level rose by about 0.3 inches (0.76 centimeters) from 2022 to 2023, a relatively large jump due mostly to a warming climate and the development of a strong El Niño. The total rise is equivalent to draining a quarter of Lake Superior into the ocean over the course of a year.

Marine heat waves will become a regular occurrence in the Arctic in the near future and are a product of higher anthropogenic greenhouse-gas emissions, according to a study just released by Dr. Armineh Barkhordarian from Universität Hamburg's Cluster of Excellence for climate research CLICCS. Since 2007, conditions in the Arctic have shifted, as confirmed by data recently published in the journal Communications Earth & Environment. Between 2007 and 2021, the marginal zones of the Arctic Ocean experienced 11 marine heat waves, producing an average temperature rise of 2.2 degrees Celsius above seasonal norm and lasting an average of 37 days. Since 2015, there have been Arctic marine heat waves every year.

In March and April 2023, some Earth scientists began to point out that average sea surface temperatures had surpassed the highest levels seen in a key data record maintained by NOAA. Months later, they remain at record levels, with global sea surface temperatures 0.99°C (1.78°F) above average in July. That was the fourth consecutive month they were at record levels.

f global warming reaches or exceeds two degrees Celsius by 2100, University of Western Ontario's Joshua Pearce says it is likely that mainly richer humans will be responsible for the death of roughly one billion mainly poorer humans over the next century. The oil and gas industry, which includes many of the most profitable and powerful businesses in the world, is directly and indirectly responsible for more than 40% of carbon emissions—impacting the lives of billions of people, many living in the world's most remote and low-resourced communities. A new study proposes aggressive energy policies that would enable immediate and substantive decreases to carbon emissions and recommends a heightened level of government, corporate and citizen action to accelerate the decarbonization of the global economy, aiming to minimize the number of projected human deaths.

Population ecologist William Rees, with the University of British Columbia's School of Community and Regional Planning, is reminding denizens of Earth that the planet can only support so many people. In his paper published in the journal World, he points out that many models have been developed over the years that show that only a certain number of animals (such as rats) can live in a given environment—they all show that at some point, a population correction occurs.

As the Arctic warms, shrinking glaciers are exposing bubbling groundwater springs which could provide an underestimated source of the potent greenhouse gas methane, finds new research published in Nature Geoscience. The study, led by researchers from the University of Cambridge and the University Center in Svalbard, Norway, identified large stocks of methane gas leaking from groundwater springs unveiled by melting glaciers.

Around the world, rainforests are becoming savanna or farmland, savanna is drying out and turning into desert, and icy tundra is thawing. Indeed, scientific studies have now recorded "regime shifts" like these in more than 20 different types of ecosystem where tipping points have been passed. Around the world, more than 20% of ecosystems are in danger of shifting or collapsing into something different.

In early May, a groundbreaking study from the University of California, San Francisco of 171 pregnant women found more than 9 in 10 had measurable amounts of 19 different chemicals and pesticides in their bodies. Researchers said many of those substances pass through the placenta and into developing fetuses, adding evidence to a National Institutes of Health report that warned babies are born "pre-polluted" with chemicals.

Current climate policies will leave more than a fifth of humanity exposed to dangerously hot temperatures by 2100, new research suggests. The paper, published in the journal Nature Sustainability, is entitled "Quantifying the Human Cost of Global Warming."

Humanity is not on track to avoid the deadliest effects of climate change, according to University at Buffalo researcher Holly Jean Buck. "Our plans are not adequate to meet the goal of limiting the Earth's temperature increase to no more than 1.5℃ by 2050," said Buck, Ph.D., assistant professor of environment and sustainability....

The Greenland Ice Sheet covers 1.7 million square kilometers (660,200 square miles) in the Arctic. If it melts entirely, global sea level would rise about 7 meters (23 feet), but scientists aren't sure how quickly the ice sheet could melt. Modeling tipping points, which are critical thresholds where a system behavior irreversibly changes, helps researchers find out when that melt might occur.

Microplastic pollution reduces energy production in a microscopic creature found in freshwater worldwide, new research shows. Paramecium bursaria contain algae that live inside their cells and provide energy by photosynthesis. The results of a NEW STUDY showed a 50% decline in net photosynthesis—a major impact on the algae's ability to produce energy and release oxygen

The damage functions in the models, which relate GDP to temperature and sea-level rise, account for impacts on agriculture, forestry, fisheries, floods, road infrastructure, energy supply and demand, and labor productivity. Using this novel approach, the researchers estimate that the avoided damages are 1.5-3.9 times higher than the costs of climate mitigation. In other words, one euro invested in climate solutions saves the world about 1.5 to 4 euros in effects from climate change.