Key developments
African forests flipped to net carbon source
New satellite, machine-learning, and ground-based analysis reported today says African forests switched from net carbon uptake in 2007-2010 to net emissions after 2010. The study estimates biomass losses of about 106 billion kilograms per year from 2010 to 2017, with the biggest declines in tropical moist broadleaf forests, especially in the Democratic Republic of Congo, Madagascar, and parts of West Africa. Some savanna areas gained biomass, but not enough to offset the broader reversal.
Why it matters
A major land carbon sink appears to have become a net emitter, worsening the challenge of meeting climate targets.
Sources & driving stories
SCIENCEDAILY
ScienceDaily coverageAMOC collapse may release stored carbon
New modeling reported by New Scientist says a full collapse of the Atlantic Meridional Overturning Circulation could trigger deep mixing in the Southern Ocean and release as much as 640 billion tonnes of carbon dioxide. The study estimates that would add about 0.2C of warming and that shutdown would not recover in scenarios at or above 350 ppm atmospheric CO2. With current concentrations near 430 ppm, the paper frames the risk as potentially irreversible if collapse occurs.
Why it matters
It links a major ocean circulation tipping point to a large additional carbon feedback and extra warming.
Sources & driving stories
NEW SCIENTIST
New Scientist coverageBetter heat forecasts could cut mortality
University of Arizona-led research using day-ahead National Weather Service forecasts, PRISM weather data, and county mortality records found that underestimating hot conditions is the most dangerous forecast error for heat deaths. The authors built optimistic, pessimistic, and perfectly accurate future forecast scenarios from a 2025 meteorologist survey and estimated that improved short-term forecasting could reduce U.S. heat mortality by 18% to 25% in 2100 across warming futures of 1.6C to 3.8C. The projected benefit rises as extreme heat intensifies.
Why it matters
It identifies weather forecasting quality as a concrete adaptation lever for reducing heat-related deaths.
Sources & driving stories
EUREKALERT!
EurekAlert! coverageWorth noting
WORTH NOTING
Interior Antarctica is warming unevenly
A new paper reports overall Antarctic warming but weaker-than-modeled warming in the interior, with strong regional contrasts that matter for future projections.
WORTH NOTING
PacifiCorp drops wind and solar expansion
The utility's updated long-range plan says no new wind or solar facilities in several states from 2027 through 2045, signaling a major planning shift.
WORTH NOTING
India's clean energy depends on debt markets
An IEEFA report says renewable expansion will require much more long-tenor financing, making bond-market structure central to India's transition pace.
Still unclear
OPEN QUESTION
Can better forecasts blunt heat mortality?
The mortality reduction estimate depends on whether forecast improvements, staffing, and dissemination actually keep pace with rising heat risk.
OPEN QUESTION
Is AMOC collapse irreversible at today's CO2?
The modeled non-recovery threshold is far below current atmospheric CO2, but the real-world tipping-point uncertainty remains large.