Climate change has been at the top of the agenda for many nations across the world. Why would some global leaders otherwise appoint ‘chief heat officers’, who have the most important tasks at hand—to deal with rising temperatures in their respective cities?
Athens, the capital of Greece, has had a chief heat officer since 2021, so does Miami in Florida and Phoenix in Arizona in the US, and Freetown, the capital of Sierra Leone, in West Africa. The idea is to coordinate efforts and protect people from the heat and save lives.
Since 2021, summer temperatures in Athens have reached as high as 45 degrees Celsius (°C), wildfires have created havoc in the region and many people have died from the prolonged heat. It is in such a situation that the city’s chief heat officer—Eleni Myrivili—has been finding ways to promote greener spaces and landscape design that sheds heat and cope up strategies for residents. The primary goal is to avoid the worst effects of global heating.
Wildfires, hurricanes, and floods may have garnered headlines and been the cause of most deaths and disasters around the world, but the dangers of global heating are real and are leading to extreme heat waves and rising temperatures, which are in turn are a consequence of climate change over the past few years.
Intense heat waves are now common in most parts of the world. India, Spain and the US have set provisional records in exceptionally high temperatures. Spain set a new heat record of 47.2°C in August last year. Many places in the US, like in the states of Oregon and Washington, and the western provinces of Canada recorded temperatures far above 40°C last year.
Over the past decade, daily record high temperatures have occurred twice as often as record lows across the continental United States. “Heat waves are occurring more often than they used to in major cities across the US and European countries. Their frequency has increased steadily, from an average of two heat waves per year during the 1960s to six during the 2010s. Heat waves have become more intense and of longer duration over time. This shift in weather conditions is significant and related to global warming,” says Dr Jyoti Kumar Sharma, professor and head, Centre for Environmental Sciences & Engineering (CESE), School of Natural Sciences (SNS), Shiv Nadar University, Delhi-NCR.
The United Nations Intergovernmental Panel on Climate Change (IPCC) has warned that heat waves and humidity-related heat stress will intensify in South Asia. In fact, heat waves on land have started early in India this year with extreme temperatures in northwest India and Rajasthan, Gujarat, Uttar Pradesh and New Delhi being the worst hit.
Data suggest that India recorded its warmest March in 122 years with a severe heat wave scorching large swathes of the country this year. Similarly, April, too, was hottest in 122 years with average maximum temperatures reaching 35.9°C and 37.78°C in northwest and central India, respectively.
The national capital for the first time in 72 years recorded a high temperature in April with 42.4°C on April 9. The all-time highest maximum temperature for the month was 45.6°C on April 29, 1941. Heat wave conditions seared Alwar in Rajasthan with a maximum temperature of 45.8°C.
A prolonged dry spell has led to severe hot weather conditions in northwest India and the adjoining parts of central India saw more intense and frequent heat wave conditions in April, said the India Meteorological Department (IMD). “The last two years saw no heat waves but regular summer. So, there’s enough evidence that heat waves are not happening every year. But this year, it is recurring for more than three weeks, starting in March with Rajasthan, Haryana, Himachal Pradesh and Delhi, and will remain so for some time until the first week of July. The frequency and severity of weather conditions will increase like we have dense fog, heavy rain, cyclones, and thunderstorms,” says RK Jenamani, senior scientist, National Weather Forecasting Centre, India Meteorological Department IMD).
IMD director general Mrutyunjay Mohapatra says northwest and west central parts of the country—Gujarat, Rajasthan, Punjab and Haryana— will continue to experience above normal temperatures in May as well. Nights would be warmer in May in most parts of the country, except some regions of south peninsular India, Mohapatra adds.
For the plains, a ‘heat wave’ is declared when the maximum temperature is over 40°C and at least 4.5 notches above normal. A ‘severe heat wave’ is declared if the departure from normal temperature is more than 6.4 notches, according to IMD. The weather department attributed the heat to the lack of rainfall due to the absence of active western disturbances over north India and any major system over south India. “Usually, because of the western disturbance, northwest India gets rainfall in March and early April. With high-pressure build-up over northern India, and no western disturbance, it has resulted in high temperatures. The prolonged dry period, along with the prevailing warm south-westerly winds from Rajasthan, is leading to an early rise in temperature, which is generally predicted in the latter week of April or May,” says Santosh Kumar Muriki, Associate Fellow, Earth Science and Climate Change Division, The Energy and Resources Institute (TERI). “Due to intensification of climate change, the traditional global circulation pattern, such as the jet stream in the northern hemisphere, is expected across the planet, leading to more frequent and intense extreme climate events,” he adds.
Weather forecasting services Skymet in its monsoon forecast for 2022 estimated a ‘normal’ monsoon of the long period average of 880.6mm for the four-month-long period from June to September. According to Yogesh Patil, CEO, Skymet, “The last two monsoon seasons have been driven by back-to-back La Nina events (strong winds push warm water towards Asia and upwelling increases of the west coast of the Americas). Earlier, La Nina had started shrinking sharply in winters, but its fallback has been stalled on account of the strengthening of trade winds. Though it has passed its peak, La Nina cooling of the Pacific Ocean is likely to prevail till, short of the onset of southwest monsoon. Therefore, the occurrence of El Nino, which normally corrupts the monsoon, is ruled out. However, pulsating behaviour of the monsoon is expected to transpire abrupt and intense rains, interspersed by abnormally long dry spells.”
Rajasthan and Gujarat along with Nagaland, Manipur, Mizoram and Tripura of the northeast region are to be at risk of being rain deficit throughout the season. Monsoon is likely to make a decent start during the onset month of June. Thus, the absence of pre-monsoon showers in central India has contributed to dry and hot conditions.
The latest IPCC report is an alarming assessment on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission. In many ways, global warming will have a deep impact on people across the globe. While coastal cities are facing the highest climate risks as sea-level rises and avoiding new development in high-risk locations, urban lands are not far behind.
“Coldest winter, hottest summer, floods, droughts and forest fire… all these are unprecedented events happening because of climate change. It’s the chain of events that cause all the extreme and erratic weather conditions sweeping large parts of the world and are now becoming frequent,” says Bengaluru-based climate scientist NH Ravindranath, former professor at the Indian Institute of Science (IISc), Bengaluru. Ravindranath has recently worked with the Union ministry of environment, forests and climate change (MoEFCC) contributing to the assessment of impact of climate change on the forest sector.
Global heating of the poles and ice in the Arctic and Antarctica is causing significant sea-level rises which is a cause of danger. Scientists at the panel of IPCC report warned the Earth’s polar region is already going through ‘irreversible’ changes. Antarctica may see a significant increase in the number of days above freezing in certain parts of the continent—50 additional days per year by 2100. The Arctic climate change impacts are already occurring ‘much faster’ than in any other region.
Sea-ice decline has been connected to increasing air temperatures at high latitudes and can change the Earth’s energy balance, leading to either a warming or cooling effect over time. The US Environmental Protection Agency estimates: From 1990 to 2019, the total warming effect from greenhouse gases added by humans to the Earth’s atmosphere increased by 45%. The warming effect associated with carbon dioxide alone increased by 36%.
“As greenhouse gases increase, they build up in the atmosphere and warm the climate, leading to many other changes around the world—in the atmosphere, on land, and in the oceans,” says Ravindranath.
Take for instance, the average global crop yields for maize, or corn, which may see a decrease of 24% by the late century, with the declines becoming apparent by 2030, with high greenhouse gas emissions, according to a new NASA study. Climate change may affect the production of maize (corn) and wheat as early as 2030 under a high greenhouse gas emissions scenario, according to a new NASA study published in the journal, Nature Food. Maize crop yields are projected to decline 24%, while wheat could potentially see growth of about 17%.
“The next 15 years’ timescale requires a detailed study on how crop and pollination will be affected with climate change. Europe and the US already have a long-term study in this sector,” adds Ravindranath.
Not just the poles, the ‘Horn of Africa’— comprising Somalia, Ethiopia, Djibouti and Eritrea—is facing its worst drought in 40 years, recording its driest conditions since 1981. It has not been receiving the required amount of rainfall for three consecutive seasons since October 2020. Experts cite a number of reasons, including climate change, behind this deficit.
Climate change, spurred by fossil fuel use and other polluting human activities, intensifies heat waves and makes them more frequent, according to the IPCC report. In 2019, the Swiss held funerals for ice lost to global warming at the Pizol glacier in the Glarus Alps of northeastern Switzerland. The glacier lost about 80% of its volume since 2006, a trend accelerated by rising global temperatures. A study also suggests more than 90% of Alpine glaciers will disappear by 2100 if greenhouse gas emissions are left unchecked. It is also estimated that up to 630 million people could be forced to leave their homes as a result of a rise in sea levels by 2 metres by 2100.
Rising climate change may even shift city capitals. Indonesia plans to move its capital from the traffic-choked city of Jakarta to the island of Borneo as Jakarta is sinking by an average of 1-15 cm a year. The move would cost up to $33billion (£27billion) and require an area of 30,000 to 40,000 hectares to house between 900,000 and 1.5 million people.
Until 1991, Lagos, the largest city in Nigeria, was its capital. Reasons for moving the capital to Abuja were its central location, away from the coast. Lagos was congested, Abuja is a planned city—the first in Nigeria.
California experienced the largest wildfires in modern history with millions suffering from air quality due to heat-triggered smog and fire smoke in 2020. While China announced it would become carbon net-zero by the year 2060, it is the world’s biggest greenhouse gas emitter, contributing to 30% of all global emissions, due to coal fired electric generation and industrial emissions.
Phoenix in Arizona experienced its hottest summer on record in 2021, with more than 114 days where the thermometer tipped past 100 degrees Fahrenheit (around 37.8°C).
Now or never
As global carbon neutrality by 2050 is the only way to achieve the Paris Agreement target at the current rate of emissions, the world is headed for a 3 to 4°C rise in temperatures by 2100. The Paris Accord is a good start, but it is only a recommendation and not a legal obligation.
Climate change is an intertwined issue; so, the challenge is to address the key developmental issues in the most climate-friendly way. How do we provide electricity with renewables playing an important role or thermal comfort through affordable housing? How do we ensure there are more urban forests and biodiversity corridors? These are some of the questions that need to be addressed.
For instance, there should be increased use of public transport, as pollution and congestion emanating from frequent private vehicle usage is dangerous. Flyovers are no longer a solution for traffic congestion, as its construction not only costs many trees, but creates heat islands.
Urban greening is often explained as a solution to tackle heat waves or floods through green and natural urban spaces, community gardens, green corridors, etc. The construction building material impacts the environment as most urban cities use concrete material and steel that absorb heat. The use of sustainable materials in construction or constructing a water body indoors can help. Most architectural designs have switched to exteriors utilising organic elements like verdant vertical gardens, large windows and ventilated buildings.
According to findings by the Washington-based US Green Building Council, buildings alone consist of around 41% of the global energy use. Concrete can be replaced with the use of alternative construction materials like hempcrete or hemplime, a mixture of hemp hurds and lime, a lightweight insulating material ideal for most climates as it combines insulation and thermal mass. Recycled scrap steel, ideal for eco-building construction material can be used for beams, girders and other structural components. It reduces the energy impact by 75%. Solar tiles help generate power for the building’s inhabitants and protect the roof top from the sun.
“A paradigm shift is required for city architecture and design that are heavily populated by roads, pavements, buildings made of concrete and steel that absorb heat. A short term measure can be to paint roofs in white to reflect light, window placements that enhance airflow or support green spaces, and no use of glass façade in architecture as it absorbs heat,” says climate scientist Ravindranath.
Kumar of Shiv Nadar University suggests how this year’s report by the Natural Resources Defense Council on ‘Expanding Heat Resilience Across India’ has stressed the need to build resilience at the city level in addition to state initiatives. “City leaders have a clear mandate to protect residents and can employ local means of communication to reach the public,” he quotes the report.
“A state’s heat action plans should be prepared, which should incorporate five core elements: Community outreach to build awareness, early warning systems to alert the public, training of healthcare workers, focussing on the vulnerable population such as farmers, construction workers, traffic police, implementing adaptive measures such as providing drinking water, cooling centres, gardens, shade spaces during extreme heat days,” says the report.
According to UNEP’s Emissions Gap Report 2021, the global rise in temperature this century can be significantly reduced if countries pledge to net-zero emissions by 2050. In fact, urban heat islands often amplify the impacts of heat waves in cities. Cities need biodiversity and plantation drives to not just transform urban heat islands with vegetation but also help to improve air quality and canopy coverage.
While energy efficiency has become one of the hottest trends in vehicle, appliance and equipment design, building structures and systems that protect and preserve natural resources while still meeting human needs are now important. “A green building design emphasises low-energy usage and as much reliance on natural light and ambient conditions as possible. Technology can enable micro-precision control over every aspect of heating, lighting, cooling, air and maintenance by employing sensors and AI-based systems that automatically detect room usage and outside conditions and adjust heating, lighting and ventilation to optimal levels. This ensures that only as much energy as is necessary is used at any given time, which reduces carbon emissions and also saves on energy costs,” says Gaurav Burman, VP & APAC president, 75F, an IoT-based building automation system in India.
Mahindra Lifespace Developers, the real estate and infrastructure development arm of the Mahindra Group, has launched its first net-zero energy residential project in Bengaluru, Mahindra Eden. The features are expected to save over 1.8 million kWh electricity annually, equivalent to powering over 800 homes. The remaining energy demand for the project will be met from renewable sources through both on-site solar and wind energy systems, and purchase of green energy from the grid.
“Global climate change is one of the most pressing issues and buildings alone are responsible for approximately 36% of the total energy consumption and close to 40% of carbon emissions. We are committed to play a leading role in energy transition and building net-zero homes, an important solution to climate change and the real estate sector,” says Arvind Subramanian, managing director and CEO, Mahindra Lifespace Developers Limited.
Mahindra Eden has been developed by adopting climate responsive design strategies and energy conservation measures that include optimal building orientation to maximise natural light and ventilation, optimum shading for windows and balcony, solar reflective index paints on roof and exterior walls for high heat reflectivity, high-performance glass on windows and balcony to reduce heat ingress from the building envelope and energy-efficient lighting and equipment.