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Water Wisdom: Climate change and heat wave

Contribution of climate change to fire risk would be lower if greenhouse gas emissions were curtailed.

BySanjenbam Jugeshwor Singh

Updated 20 Nov 2023, 12:33 am

Representational Image (Photo: Pixabay)
Representational Image (Photo: Pixabay)

This monsoon, when the precious rainwater goes down the drain, let us take a moment to recapitulate the knowledge of water management and what it means in a climate-risked world. There are two incontrovertible facts: one, water is a key determinant of health security and economic growth. Two, water wars are not inevitable but will happen if we do not manage our resource prudently. This requires us to get the policy and practice of water management right.

The good news is water literacy has increased. Over the past decades, the country has learnt critical lessons on water management and evolved a new paradigm. Till the late 1980s, water management was largely confined to the issue of irrigation projects — building dams and canals to store and supply water over long distances. Then came the big droughts of late 1980s. It became clear that it was not enough to plan for augmenting water supply through large projects. This was when the Centre for Science and Environment published its report, Dying Wisdom, which documented traditional technologies for rainwater harvesting in ecological diverse regions of India.

The slogan was: rain is decentralized, so is the demand for water. So, capture rain when and where it falls. There was a paradigm shift in policy. During the droughts of the late 1990s, states launched massive programmes to capture rainwater by building ponds, digging tanks and setting up check-dams on streams. By the mid-2000s, these efforts coalesced into the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) — investing labour into building rural water assets.

By this time, it was understood that groundwater, considered a “minor” resource was the “major” supplier of water for both drinking and irrigation. It was understood that over 50 per cent of agriculture in the country was still rain-fed, and so water conservation and rainwater harvesting — ensuring that every well and water body was recharged — was critical for productivity and well-being.

In the 2010s, the crisis of urban drought hit home. Policy evolved as it learnt that augmenting water supply was only a part of the challenge — cities were getting dependent on long-distance sources; pumping and piping this water meant losses in distribution and rising electricity costs, which made the available water expensive and its supply inequitable.

As water supply dried up, people turned to groundwater, but without recharge — ponds and tanks had been decimated by real estate or simply through neglect— it only meant declining water levels. That was the decade when water supply was linked to pollution — more water supply meant more wastewater. This, without adequate treatment, leads to pollution of rivers and water bodies, which in turn destroys available water; increases the cost of cleaning up drinking water.

A few years later, research showed that the bulk of urban residents were not even connected to underground sewerage network, which is capital- and resource-intensive. Instead, they depended on on-site sewage ”disposal” systems, where household toilets were connected to septic tanks or just holding tanks or even to open drains in the vicinity.

The sewage treatment infrastructure was not designed to fit the city sanitation system and so remained underutilized as is done in Sewage Treatment Project of Imphal City. Rivers remained polluted as seen in Nambul, Imphal and Thoubal Rivers. In all this, new solutions emerged — if affordable water supply was critical, then cities needed to cut the length of distribution pipelines, which meant increased focus on local water systems like ponds, tanks and rainwater harvesting structures.

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Then, if cities needed to ensure affordable sanitation for all and affordable treatment of wastewater, on-site systems could be re-engineered so that waste was collected from each household, transported and treated. But most importantly, we have learnt that if this urban-industrial wastewater is treated for reuse then water will not be lost; our rivers will not be lost. This means, doing everything from investing in water-efficient irrigation and household appliances to changing diets to ensure that the crops we eat are water-prude.

 

This decade, we can put all that we have learnt into practice to turn around the water story of India, as in this decade we will see the revenge of nature as climate change impacts grow. We need to scale up our work to invest in local water systems to capture every drop of rain so that we can build local resilience against drought. We also need to do this in our cities — the lakes and ponds are the sponges that will allow us to harvest the rain-flood and to make sure it does not turn into wasted water.

Then we need to protect our forest and green spaces as this is how groundwater will get recharged. In times of water stress we must make sure that wastewater — sewage — is not only treated but also recycled and reused. It is here that the water bodies we protect in our cities — the same ponds and tanks that we use to divert and harvest rainwater — could be used to channelise the treated sewage and in turn recharge groundwater. Only this approach can make us water-secure.

Heat waves have been going through some extraordinary changes in recent history. Since midway through the 20th century, their intensity, frequency and duration have increased across the globe – and these changes are happening faster and faster. Research indicates that this is simply not possible without human influence on the climate. A child born today could see an extra 30 to 50 heat wave days every year by the time they are 80, up from roughly 4 to 10 days today.

Southern states of Australia, such as Victoria and South Australia, which already experience the country’s hottest heat waves, could see hot days become hotter by up to 4 degrees Celsius. Across Europe, heat waves may become hotter by up to 10 degrees Celsius and some heat waves will last up to two months by the end of this century. In just the next 20 years, the US will experience three to five more heat waves every decade compared to the second half of the 20th century.

Heat waves are closely linked to droughts. Generally, a large amount of energy from the Sun goes into drying out moisture in the landscape. But as the amount of moisture available for evaporation declines during a drought, more energy is available for heating the air and the temperature rises. This can become a vicious cycle of increasing evaporation and desiccation of the land surface. And of course, during times of heat waves and droughts, wildfires will ignite more readily, burn more intensely and spread faster.

The link between wildfire and heat waves has been seen across the world in numerous examples. The Australian 2019-20 fire season, known as the ‘Black Summer’, saw huge areas of the populated eastern seaboard dramatically ablaze. The fact that it coincided with Australia’s hottest and driest year on record was no accident. Extreme fire weather rolled across the continent on an almost weekly basis.

First a heat wave would develop across southeast Australia, with hot and dry air funneled from the center of the continent drying out dead litter and branches and even live vegetation. This, combined with strong north-westerly winds forming ahead of a cold front, required just a spark to result in what became known as ‘firestorms’. Then, the cold front would arrive; further escalating fire behaviour and triggering thunderstorms and lightning strikes – many of which would flare into the next round of wildfires.

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Deep and extensive drought all but guaranteed the fires found fuel that was fully available to burn. In lock-step with heat waves, wildfires are a worsening global problem and extreme wildfires, in particular, are affecting fire-prone regions such as western North America, Eastern Russia, and Mediterranean Europe. 

For example, the Russian heat wave in 2010 when 300,000 hectares were destroyed by simultaneous wildfires; the 2016 western Canadian heat wave and the Fort McMurray wildfire; and the more recent 2021 record heat wave in British Columbia where temperature records were smashed by up to 5°C, and which was immediately followed by the destruction of the town of Lytton by wildfire. With climate change driving more heat waves, associated weather and climate-related factors will increase the incidence of extreme wildfires. 

A Royal Commission initiated after Australia’s Black Summer fire disaster pointed to an urgent need to improve disaster management capabilities in order to respond to more frequent, intense, complex and costly fires under a changing climate. This can be done in all of three ways: first, limit the vulnerability of communities and ecosystems to fire; second, limit communities and ecosystems exposure to fire; third, limit the fire itself. 

For example, improving community information and fire preparedness reduces vulnerability. Improved development planning, building standards and management of the forest-urban boundary reduces exposure. Land management that reduces the opportunity for large fires to develop, or firefighting to extinguish fires once they start, reduces the fire itself. 

Information about forest dryness is useful for early warning and preparedness for extreme fires. Similarly, mapping climate variability across many years can help predict extreme years. Recommendations of the Royal Commission included improving national systems of collecting and sharing bushfire related information, including information on climate change and fuel loads. ‘Hazard reduction burns’ are a practice that is widely used to reduce forest fire risk in Australia.

However, scientific studies have found no clear indication of how much fuel load matters in extreme wildfires. Given that fuel loads are one of the few elements of fire that humans can control, this is concerning, as it suggests hazard reduction burning may be of only limited effectiveness. Of course, there are limits to how much the risk of wildfires can be mitigated.

As climate change moves fire outside of the range of human experience, disaster management will become increasingly challenging and potentially less effective. While efforts can be made to limit vulnerability, exposure and fire itself, it is clear that the contribution of climate change to fire risk would be lower if greenhouse gas emissions were curtailed. Pursuing ambitious global greenhouse gas mitigation alongside national and local measures to adapt to a climate changed world is a necessary strategy if we are to limit further increases in fire risk.

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First published:

Tags:

climate changeglobal warmingheat wave

Sanjenbam Jugeshwor Singh

Sanjenbam Jugeshwor Singh

Assistant Professor, JCRE Global College, Babupara, Imphal. The writer can be reached at sjugeshwor7@gmail.com

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