The Third Pole (TP) is experiencing rapid warming and is currently in its warmest period in the past 2,000 years. This paper reviews the latest development in multidisciplinary TP research associated with this warming. The rapid warming facilitates intense and broad glacier melt over most of the TP, although some glaciers in the northwest are advancing. By heating the atmosphere and reducing snow/ice albedo, aerosols also contribute to the glaciers melting. Glacier melt is accompanied by lake expansion and intensification of the water cycle over the TP. Precipitation has increased over the eastern and northwestern TP. Meanwhile, the TP is greening and most regions are experiencing advancing phenological trends, although over the southwest there is a spring phenological delay mainly in response to the recent decline in spring precipitation. Atmospheric and terrestrial thermal and dynamical processes over the TP affect the Asian monsoon at different scales. Recent evidence indicates substantial roles that mesoscale convective systems play in the TP’s precipitation as well as an association between soil moisture anomalies in the TP and the Indian monsoon. Moreover, an increase in geohazard events has been associated with recent environmental changes, some of which have had catastrophic consequences caused by glacial lake outbursts and landslides. Active debris flows are growing in both frequency of occurrences and spatial scale. Meanwhile, new types of disasters, such as the twin ice avalanches in Ali in 2016, are now appearing in the region. Adaptation and mitigation measures should be taken to help societies’ preparation for future environmental challenges. Some key issues for future TP studies are also discussed.

China’s goal to achieve carbon (C) neutrality by 2060 requires scaling up photovoltaic (PV) and wind power from 1 to 10–15 PWh year⁻¹(refs. ^1–5). Following the historical rates of renewable installation¹, a recent high-resolution energy-system model⁶and forecasts based on China’s 14th Five-year Energy Development (CFED)⁷, however, only indicate that the capacity will reach 5–9.5 PWh year⁻¹by 2060. Here we show that, by individually optimizing the deployment of 3,844 new utility-scale PV and wind power plants coordinated with ultra-high-voltage (UHV) transmission and energy storage and accounting for power-load flexibility and learning dynamics, the capacity of PV and wind power can be increased from 9 PWh year⁻¹(corresponding to the CFED path) to 15 PWh year⁻¹, accompanied by a reduction in the average abatement cost from US$97 to US$6 per tonne of carbon dioxide (tCO₂). To achieve this, annualized investment in PV and wind power should ramp up from US$77 billion in 2020 (current level) to US$127 billion in the 2020s and further to US$426 billion year⁻¹in the 2050s. The large-scale deployment of PV and wind power increases income for residents in the poorest regions as co-benefits. Our results highlight the importance of upgrading power systems by building energy storage, expanding transmission capacity and adjusting power load at the demand side to reduce the economic cost of deploying PV and wind power to achieve carbon neutrality in China.

The East Asian monsoon circulation during the El Nino episodes of '86/87 and '91/92 is studied diagnostically. It is found that a southerly wind anomaly appeared in the lower troposphere along the coast of the East Asia during the mature phases of these two El Nino events. In the case of '86/87, the mature phase covered the boreal summer and the East Asian summer monsoon was intensified. On the other hand, in the case of '91/92, the northern winter was within the mature phase and the East Asian winter monsoon was weakened. Examination of the circulation features suggests that the effects of the El Nino events on the East Asian monsoon are felt through the variation of convective activities over the western equatorial Pacific. Convections in this area are strongly influenced by the evolution of sea surface temperature anomalies in the equatorial Pacific and are strongly suppressed during the mature phase, which exerts significant influences on the direct monsoonal circulation over the western tropical Pacific and the East Asia. The relationship between the East Asian monsoon and El Nino in its mature phase is also confirmed by a historical 850hPa wind dataset that covers 6 events prior to the '86/87 event. The dataset also suggests that an inverse relationship does not hold during the La Nina periods.