We need to address Bengaluru's bleak climate future

Bengaluru already seems crowded to us, but the city continues to grow steadily. By 2030, different agencies estimate that Bengaluru will contain between 15-20 million people. Given the size of the city, and the number of people in it, such growth will have major implications for our environment, health, ecology and energy use. In turn, the looming climate crisis will be a game changer in the coming decades.

Cities like Bengaluru demand voluminous amounts of energy to support industry and manufacturing, and for basic things like transport, electrification, construction and cooking. Even more basic needs must be satisfied – food and water amongst them. Most Indian cities consume large amounts of energy to ensure water supply. Bengaluru is no exception. The city brings water all the way from the Cauvery, across a distance of almost 100 km, pumps it up to a height of close to 500 m, and then sends it across the city in a network of pipes. The Bengaluru Water Supply and Sewerage Board spends a substantial fraction of its monthly revenue on electricity, giving us a glimpse of the massive amounts of energy this exercise requires. Yet even the water brought in at great expense from the Cauvery is insufficient to supply Bengaluru’s needs. Almost half of this water goes waste, victim to leaky pipes and unregistered usage. The need for additional water is met by private entrepreneurs, who run borewells around the clock, using up more electricity.

Cities like Bengaluru also guzzle cement like they guzzle water. Road expansion, the construction of new airports, high rise apartments and swanky corporate campuses, demand cement. Cement production requires energy. Most of the electricity that lights up homes, malls, and offices, and powers our industries, comes from coal. Indian coal plants generate close to 3/4th of the country’s energy needs. Although the supply from “clean” sources such as solar and wind energy is growing, renewable energy supply has been unable to keep pace with the accelerating demand for energy in India’s cities. Coal contributes as much as 40% to global greenhouse gas emissions, fueling the out-of-control heating of the world’s atmosphere, placing the planet’s climate on a runaway trajectory towards extremes of temperature never before witnessed in human history. The petrol and diesel that powers the tens of millions of vehicles on India’s city streets further fuels global warming. The greenhouse gases emitted by landfills and dumps, waste-to-energy plants, thermal power plants and the smoke from factory chimneys add up, increasing the scale of the problem.

Cities like Bengaluru are major drivers of climate change. The relationship goes both ways – Bengaluru is also a major location of climate impact. Although people talk a lot about coastal flooding because of climate change, it is not just cities like Mumbai, Chennai and Kolkata that will be hard hit. Inland cities like Delhi, Hyderabad and Bengaluru are already located in drought-prone low rainfall regions and face regular water shortage problems. A couple of years ago, the newspapers were filled with discussions about when Bengaluru might face Ground Zero – a day when the city runs out of water. With the new entry of Cauvery water to peripheral parts of Bengaluru, that day has been pushed into the future. But we are not safe yet. Cities like Bengaluru have become large islands of concrete. This concrete generates well-known urban heat island effects, creating super-hot pockets of air that can change local rainfall patterns, leading to even more variable rainfall. Not just Bengaluru, with global climate change, the Cauvery basin that supplies water to the city will experience increasingly erratic and unpredictable rainfall. When it does rain, way too much rainfall will be packed into short intense storms (leading to flooding). We are also likely to face longer dry spells than we are used to.

While we are dealing with Covid, we cannot afford to ignore the effects of climate change. One crisis will not wait for another.

(Harini Nagendra the Azim Premji University Prof prides herself on barking up all trees, right and wrong)