Scattered showers: Some parts of the country witnessed extreme rainfall and floods, while others remained dry, affecting the crop production there. Photo: Wikimedia Commons_Rakesh.5suthar

Heavy rain lashes South India, but eludes north, northwest; delayed monsoon withdrawal likely

South India witnessed record levels of rain this past fortnight. Heavy rain was reported in Tamil Nadu, Karnataka, Kerala, Telangana and Andhra Pradesh. Bangalore crossed the 1,000mm mark for the first time ever this southwest monsoon season. Mumbai and its neighbouring areas also recorded heavy rain with thunderstorms and lightning strikes. 

Farmers in the north, however, are suffering because of a prolonged break from rain. Rajasthan, especially, hasn’t received rain for more than a fortnight. The unusually hot temperatures have ripened the kharif crops prematurely or burnt them in some cases. Churu, Rajasthan, recorded a maximum temperature of 41°C last week

The India Meteorological Department, however, predicted a fresh spell of rain for northwest India, including Rajasthan. Heavy rainfall over Uttar Pradesh and Uttarakhand over the last week did bring some respite, but it will now also delay the withdrawal of the southwest monsoon. The normal withdrawal date is September 17, but last year, it withdrew in mid-October.  

Exceeding 1.5°C warming could trigger multiple climate tipping points: Study

As the world becomes hotter with every passing day, there’s a growing risk to set off multiple climate tipping points (CTPs), according to recent research. Climate tipping points are conditions beyond which changes in a part of the climate system become self-perpetuating beyond a warming threshold. These changes may lead to abrupt, irreversible, and dangerous impacts with serious implications for humanity. 

The research identified nine global “core” tipping elements that contribute substantially to earth system functioning and seven regional “impact” tipping elements that contribute substantially to human welfare or have great value as unique features of the earth system. The study mapped that the current global warming of ~1.1°C above pre-industrial levels already lies within the lower end of five CTP uncertainty ranges. Six CTPs become likely (with a further four possible) within the Paris Agreement range of 1.5 to <2°C warming. 

Declining crop yields due to global warming could hinder bioenergy’s potential: Study

A new study found that declining crop yields because of warming climate are likely to reduce the effectiveness of bioenergy with carbon capture and storage (BECCS). BECCS includes the burning of biomass for energy, and the resultant emissions are captured. This “negative” emissions technology plays a major role in model pathways limiting warming to 1.5-2°C. The study, published in Nature, assumed that both biofuels and the residue from food crops are used for BECCS. With the increase in global temperatures, crop yield will also decline, as will its residue. If the warming threshold crosses 2.5°C, the effectiveness of BECCS will “rapidly decrease”, according to the study. Models relying on BECCS to limit global warming could be “unduly optimistic”, according to the authors. 

Warming-induced shift in precipitation patterns leading to rapid glacier mass loss in southeastern Tibetan plateau: Study

Less summer snowfall is likely the reason for the rapidly melting glaciers in south-eastern Tibet, according to a new study. Glaciers in this region receive the most amount of snowfall in the summer months. But rising temperatures have led to a shift in summer precipitation from snow to rain. This has limited the amount of snow that accumulates on the glacier, which eventually turns to ice. This coupled with an increase in glacier melt has resulted in a rapid loss of mass in the region, according to the study published in Proceedings of the National Academy of Sciences.