March 2026 science summary

Greetings,

Apologies for the double email last month! Hopefully the new platform will work right from here on. I've got one interesting global paper on how much freshwater we're pumping out to sea, and three on fire in the Pantanal and Brazil.

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FRESHWATER:
Chandanpurkar et al. 2025 found that all continents except Antarctica have undergone drying (decreasing water stored on land) from 2002-2024 (although Figs 1 and 5 makes that hard to see in some cases, especially tropical Africa). They expect that trend to continue. Wet areas have gotten wetter but shrunk, while dry areas have expanded (and are drying faster than wet areas are getting wetter). Groundwater depletion caused 68% of the decrease, with the remainder a mix of ice and permafrost melt in Canada, and droughts in Central America and Europe. Another scary finding: water loss from continents is causing 44% of global sea level rise, more than either Greenland (37%) or Antarctica (19%). The lower-right map in Fig 3A shows how much dryer 2019-2024 in particular have been. There's a great news article and map about this here: https://www.propublica.org/article/water-aquifers-groundwate...


FIRE IN THE PANTANAL:
Concone et al 2026 found that two years after the 2020 megafires in the Pantanal, mammal diversity had been cut in half in the park they studied (see figs 2b and c), and abundance was reduced for at least 6 spp including capybara and giant armadillos (fig 4a). They found a combo of camera traps and eDNA was important to count all species (see fig 2a). 9 spp which typically favor drier and more open habitats were only found post-fire; the authors expect that to be temporary but since extreme fires have reoccurred they may have stuck around.

Whitney et al. 2026 looks at fire history in the Pantanal split by habitat type, using a mix of charcoal and diatom composition in lake sediment cores going back 3500 years, and satellite data from the last 20. In recent years, climate moisture index is the best predictor of fire, with maximum river depth during seasonal floods being an important variable. Fig 4 shows how the long-term fire trend differs for 5 habitat types. They note that the last 400 years had been getting more rain; while they don't discuss it, cattle ranching (along with fire to clear land) was introduced about 300 years ago and the wet period may have helped to contain the fires until the drying trend from the last 2 decades or so. Upland savannas are expected to see the biggest increase in fire as drying continues (based on historic data), with seasonally-dry tropical forest the least susceptible to increased fire.

Guedes et al.2026 looked at exposure of fish in temporary wetlands to fire across Brazil. They found over 1/4 of all temporary wetlands burned, including 34% of the wetlands in protected areas. In the Pantanal all protected temporary wetlands burned and 68% of the unprotected ones burned. They note that in the dry season that fewer connections between wetlands exist for fish to escape to, and that eggs buried in soil can be killed when fires burn surrounding areas.


REFERENCES:
Chandanpurkar, H. A., Famiglietti, J. S., Gopalan, K., Wiese, D. N., Wada, Y., Kakinuma, K., Reager, J. T., & Zhang, F. (2025). Unprecedented continental drying, shrinking freshwater availability, and increasing land contributions to sea level rise. Science Advances, 11(30), 1–14. https://doi.org/10.1126/sciadv.adx0298

Concone, H. V. B., Magioli, M., Hilário, H. O., Semedo, T. B. F., Moreno, W. H. A., Saranholi, B. H., Ferreira, M. D. R., Batista, E. K. L., Botelho, M. T. de A., Lima, L. H. A., & Berlinck, C. N. (2026). Smoke on the water: Pervasive effects of megafires on the mammal fauna of the world’s largest wetland. Journal of Applied Ecology, 63(1), 1–12. https://doi.org/10.1111/1365-2664.70268

Guedes, G. H. S., & Araújo, F. G. (2026). Water and fire: Wildfires threaten fish habitats across Brazilian biomes, and protected areas offer insufficient safeguards. Biological Conservation, 315(November 2025), 111692. https://doi.org/10.1016/j.biocon.2025.111692

Whitney, B. S., Neves, D. M., Loughlin, N. J. D., D’Apolito, C., Carla, C. T., Hocking, E. P., Mayle, F. E., Power, M. J., Silva Aguinaldo, & Assine, M. L. (2026). Millennial-scale fire and climate dynamics in the world’s largest tropical wetland show emerging fire threat to flooded ecosystems. Global and Planetary Change, 259(April), 105318. https://doi.org/10.1016/j.gloplacha.2026.105318

Sincerely,

Jon

P.s. These are some baby bunnies rescued from a neighbor's window well