English references

For decades, the surface of the polar Southern Ocean (south of 50°S) has been freshening—an expected response to a warming climate. This freshening enhanced upper-ocean stratification, reducing the upward transport of subsurface heat and possibly contributing to sea ice expansion. It also limited the formation of open-ocean polynyas. Using satellite observations, we reveal a marked increase in surface salinity across the circumpolar Southern Ocean since 2015. This shift has weakened upper-ocean stratification, coinciding with a dramatic decline in Antarctic sea ice coverage. Additionally, rising salinity facilitated the reemergence of the Maud Rise polynya in the Weddell Sea, a phenomenon last observed in the mid-1970s.

Identifying the socio-economic drivers behind greenhouse gas emissions is crucial to design mitigation policies. Existing studies predominantly analyze short-term CO2 emissions from fossil fuels, neglecting long-term trends and other GHGs. We examine the drivers of all greenhouse gas emissions between 1820–2050 globally and regionally. The Industrial Revolution triggered sustained emission growth worldwide—initially through fossil fuel use in industrialized economies but also as a result of agricultural expansion and deforestation. Globally, technological innovation and energy mix changes prevented 31 (17–42) Gt CO2e emissions over two centuries. Yet these gains were dwarfed by 81 (64–97) Gt CO2e resulting from economic expansion, with regional drivers diverging sharply: population growth dominated in Latin America and Sub-Saharan Africa, while rising affluence was the main driver of emissions elsewhere. Meeting climate targets now requires the carbon intensity of GDP to decline 3 times faster than the global

Climate change will fuel contests—and maybe wars—for land and resources.

Study highlights conflict between Washington’s claims of climate leadership and its fossil fuel growth plans

Russia’s military offensive against Ukraine is an act of aggression that will make already worrisome tensions between Nato and Moscow even more dangerous. The west’s new cold war with Russia has turned hot. Vladimir Putin bears primary responsibility for this latest development, but Nato’s arrogant, tone‐​deaf policy toward Russia over the past quarter‐​century deserves a large share as well. Analysts committed to a US foreign policy of realism and restraint have warned for more than a quarter‐​century that continuing to expand the most powerful military alliance in history toward another major power would not end well. The war in Ukraine provides definitive confirmation that it did not.