Connect with us

Climate

Delhi’s Air Pollution: Climate Change Is Raising Risks for India’s Heritage

India’s heritage sites are facing growing environmental risks as air pollution, rising temperatures, changing rainfall and coastal exposure accelerate the deterioration of historic structures. From pollution-linked black crusts at Humayun’s Tomb to salt damage at Mahabalipuram’s Shore Temple, scientific studies show why climate and environmental monitoring are becoming increasingly important for heritage conservation.

Published

on

Humayun’s Tomb in Delhi surrounded by trees and gardens under a partly cloudy sky
Humayun’s Tomb in Delhi, a UNESCO World Heritage Site facing environmental pressures from air pollution and changing climate conditions. Representational image. Image credit: miheer tewari/Pexels

Delhi’s air pollution is damaging more than the city’s air quality. It is also contributing to the slow deterioration of its built heritage. India’s historic monuments are facing an environmental threat that extends beyond age and neglect. Air pollution, extreme weather, changing rainfall, rising temperatures and coastal hazards are creating new challenges for conserving structures built under very different environmental conditions.

A new study of Humayun’s Tomb in Delhi provides a close look at one of these risks. Researchers from IIT Roorkee and IIT Kanpur found that air pollution is contributing to the formation of black crusts on the sandstone surfaces of the UNESCO World Heritage Site. The study found that these crusts contain gypsum, carbon-rich material and traces of metals associated with urban pollution.

The finding is significant because it shows how environmental conditions around a monument can gradually alter its materials. But Humayun’s Tomb is only one example of a wider conservation challenge.

Pollution Leaves a Chemical Mark

Researchers collected five black-crust samples from rain-sheltered rooftop locations at Humayun’s Tomb under the supervision of an Archaeological Survey of India conservator. Using techniques including XRF, XRD, FTIR, SEM-EDX, CHNS and ICP-MS, the researchers found gypsum to be the dominant mineral in the crust. They concluded that external sources of calcium, including airborne particles, react with sulphur compounds to produce gypsum on the sandstone.

The composition also contained indicators consistent with pollution from vehicles, road and soil dust, construction, biomass burning and industrial activity. Crust formation was stronger at locations exposed to wind but sheltered from rain, showing that both pollution and local exposure conditions influence deterioration.

Heritage monument sites and climate change
Delhi’s heritage buildings are seen through heavy smog, highlighting the city’s severe air pollution. Representational image. Image credit: Saakshi Yadav/Pexels

The study does not establish that the black crust itself has caused structural failure of Humayun’s Tomb. Instead, it identifies a long-term material deterioration process and recommends preventive conservation, including scientifically established cleaning methods, site-specific testing of protective coatings, air-quality monitoring and atmospheric modelling.

The Taj Mahal Shows How Pollution Affects Heritage

Humayun’s Tomb is not the only Indian monument where air pollution has been studied as a conservation concern. A 2015 study in Environmental Science & Technology measured particulate pollution around the Taj Mahal over a year and found high levels of light-absorbing particles, including black carbon, brown carbon and dust. Experiments using marble surrogate surfaces showed that these carbon-rich particles contribute to surface discoloration.

However, this finding is specific to staining and surface change. It does not imply that air pollution alone explains all forms of deterioration at the Taj Mahal. Recognising pollution as a conservation issue, the Ministry of Culture reports that the Archaeological Survey of India operates air-pollution monitoring laboratories at the Taj Mahal and Bibi ka Maqbara.

Climate Conditions Monuments Face

Climate change presents a different, but overlapping, conservation problem. UNESCO identifies storms, cyclones and tidal surges as potential threats to the World Heritage property and notes that their frequency could increase as a result of climate change.

A major review of climate-change impacts on cultural heritage found that climate change can alter the frequency and intensity of processes that already damage historic materials. These include moisture-related deterioration, salt crystallisation, biological growth and erosion. The review stresses that the effects vary according to the material, location and local climate of each heritage site.

That makes it important not to treat climate change as a single threat to India’s monuments. A stone temple on the coast faces different risks from a sandstone monument in Delhi or a heritage structure in a flood-prone region.

Mahabalipuram: Salt and Sea Exposure

The Shore Temple at Mahabalipuram illustrates the vulnerability of coastal heritage. A study by researchers from ASI and the National Museum Institute examined the deterioration of the 7th–8th-century granite monument. Extensive salt-induced deterioration, particularly on sections directly exposed to the sea. Some sculptures on the seaward side had been eroded beyond recognition.

The study linked the deterioration to marine exposure, sea spray, soluble salts, high-velocity winds and the site’s tropical, humid conditions. The researchers also found that continuous sea spray makes some conventional stone-conservation approaches difficult to maintain.

The study does not establish that climate change caused the Shore Temple’s existing deterioration. It does, however, demonstrate how vulnerable coastal heritage can be to marine and climatic conditions; risks that become increasingly important as coastal environments change.

Importance of Preventive Conservation

India has already begun incorporating environmental monitoring into heritage conservation. The Ministry of Culture said in that ASI and ISRO have installed Automated Weather Stations at several historical monuments to track temperature, rainfall and wind. ASI also carries out periodic scientific treatment and conservation work at heritage sites.

But the evidence from Humayun’s Tomb shows that monitoring pollution and climate variables must be paired with material-level studies. The challenge is identifying the environmental drivers of deterioration and intervening early, before it becomes irreversible.

For Delhi, this means reducing pollutants that settle on historic stone. Coastal monuments must contend with salt, moisture and erosion, while high-rainfall regions require stronger drainage and structural resilience.

Climate

Record Drought and Extreme Heat Push European Rivers to Lows as Wildfires Spread North

The European drought is driving rivers to record lows as extreme heat, wildfires, crop losses and water shortages put Europe’s energy and transport systems under pressure.

Sebin Pious

Published

on

European Drought: Rivers Fall as Heat and Wildfires Spread
The Rhine at Bonn-Limperich, Germany, during an exceptionally low water level, with the Konrad Adenauer Rhine Bridge and Siebengebirge (Seven Mountains) in the background. Image credit: Sir James/Wikimedia Commons, CC BY-SA 3.0.

A prolonged European drought combined with extreme heat is pushing major rivers to record lows, disrupting shipping and energy production while worsening crop losses and wildfire risks. As dry conditions spread north, Europe’s water, agriculture, ecosystems and public health systems are coming under increasing pressure.

A long period of low rainfall combined with extreme heatwaves has placed half of the European Union and the United Kingdom under drought conditions. A report published on August 12 by the European Commission Joint Research Centre and the European Drought Observatory reveals that nine percent of the region reached a critical alert level by late July.

Satellite data from Copernicus, the Earth monitoring program of the European Union, shows that severely dry soil is now damaging crops and plants across the continent. In its latest assessment, the observatory warned that “the drought has built up since early spring due to lower rainfall and higher than average temperatures, turning into fuel for devastating wildfires.”

European Drought: Rivers Fall as Heat and Wildfires Spread
Satellite imagery shows exceptionally low water levels along four of Europe’s major rivers—the Loire in France, Po in Italy, Rhine in Germany and Danube in Hungary—in early August 2026. Exposed sandbanks and riverbeds highlight the impact of prolonged drought. Image credit: European Union, Copernicus Sentinel-2 imagery.

European Drought Reaches Across the Continent

The lack of rain has driven four of Europe’s largest rivers—the Rhine, Danube, Loire, and Po—to dangerously low levels. Near Cologne, Germany, the Rhine fell to a fresh record low of 49 centimetres by mid-August, according to the Rhine Waterways and Shipping Authority — nearly 20 centimetres below the previous record of 68 centimetres set earlier in the summer, which had itself broken the prior all-time low recorded in 2018. Because large cargo boats need deeper water to float safely, operators have been forced to carry much lighter loads to avoid getting stuck on the riverbed, and in places river traffic has largely halted. Carrying smaller loads requires more trips, creating major shipping delays for important industrial materials across central Europe.

At the same time, low water levels and rising temperatures are creating a serious energy crisis across the continent. In France, power companies had to cut back nuclear energy production because river water became too warm to safely cool reactors without harming aquatic life. Hydroelectric power generation has also plunged across the Alps, northern Italy, and central-eastern Europe. Copernicus analysts noted that low river flows on the Danube are creating “serious operational challenges” for power plant cooling. In Italy’s Po Valley, the dried-out river basin has triggered a separate disaster: saltwater from the Adriatic Sea has flowed inland into depleted channels, ruining farmland soil and cutting off freshwater supplies for local crops.

Wildfires Burn Over 550,000 Hectares Across Europe

Dry plants and extreme heat have triggered widespread wildfires across the continent. According to August 11 data from the European Forest Fire Information System, 552,437 hectares of land have burned within the European Union since the start of the year, spread across 1,614 individual fires of 30 hectares or larger. Although this total remains below the 667,342 hectares burned by the same date in 2025 — a season that went on to become the worst on record for EU wildfires, with 1,034,552 hectares burned in total — it is significantly higher than the 20-year historical average.

Recent satellite data shows a clear shift: large wildfires are no longer staying just in southern hotspots like Spain and Greece. As dry weather pushes northward, fire risks are expanding into cooler regions, including northwestern France, southern Great Britain, the Alps, and the Balkans. Experts at the Joint Research Centre emphasized that “wildfire risk is no longer confined to southern Europe but is increasingly affecting wider parts of the continent under prolonged hot and dry conditions.”

Declining Harvests and Rising Health Risks

Continued heat and dry soil are dealing a heavy blow to European farmers. According to assessments by the European Joint Research Centre, crop yields across central and eastern Europe have dropped significantly. Production estimates for key spring and summer crops, such as grain maize and sunflowers, have fallen by six to seven percent. Winter crops have also suffered, with yield forecasts declining between one and four percent compared to earlier projections.

High temperatures are having a severe impact on human health as well. Monitoring data from public health agencies and the World Health Organization reveals a sharp surge in heat-related emergency admissions and deaths during extreme temperature episodes. Data compiled from national health agencies — including Germany’s Robert Koch Institute, which alone recorded an estimated 11,900 heat-linked deaths — put the region’s heat-related death toll above 25,000 as of early August, highlighting the severe human cost of this summer’s weather.

Seasonal Outlook and Emergency Response

Weather predictions indicate that dry conditions will continue through early autumn. According to the Copernicus Climate Change Service, drier and warmer weather is expected to persist across central-western Europe and southern Scandinavia through September. Climate experts also warn that a developing El Nino pattern could keep global temperatures higher than normal well into spring 2027. “Water resources, crops, energy systems, river transport, and ecosystems are all under growing pressure,” the report warned, with heatwave risks remaining high through August.

To coordinate emergency aid, the European Union activated its Civil Protection Mechanism. A dedicated fleet of 22 firefighting aircraft, 5 helicopters, and ground teams have been placed on standby across 12 countries. Meanwhile, the Copernicus satellite service has responded to more than 30 emergency requests since June, providing real-time mapping data to help local authorities track active fires and assess land damage on the ground.

Continue Reading

Climate

Indigenous Peoples and Nature Conservation: What the Research Shows

Research shows that Indigenous Peoples and local communities play a significant role in protecting forests, biodiversity and carbon-rich ecosystems. Evidence suggests that secure land rights, traditional ecological knowledge and equitable participation in conservation governance can strengthen environmental outcomes.

Published

on

Indigenous women standing beside a large tree in a tropical forest, illustrating the relationship between Indigenous communities and nature conservation
Indigenous women stand beside a large tree in a forest, reflecting the connection between Indigenous communities, traditional knowledge and the ecosystems they help manage. Representational image. Image credit: Bill Salazar/Pexels

Climate and biodiversity policies often focus on forests protected, carbon stored and species conserved. But an increasing body of research points to another factor that can influence these outcomes: who lives in, manages and makes decisions about ecologically important landscapes.

There are an estimated 476 million Indigenous Peoples across 90 countries, representing about 6.2% of the global population. Their territories overlap with many of the world’s remaining ecologically important landscapes, making their role increasingly relevant to climate and biodiversity policy.

The evidence does not support the blanket claim that Indigenous Peoples are inherently better conservationists. It does, however, show that land rights, ecological knowledge and meaningful participation in environmental governance can be important to conservation outcomes.

Indigenous Lands Overlap With Important Ecosystems

A 2018 study published in Nature Sustainability mapped Indigenous lands across 87 countries and politically distinct areas. It estimated that Indigenous Peoples manage or have tenure rights over at least 38 million sq km, more than one-quarter of the world’s terrestrial surface.

Their territories intersect approximately 40% of terrestrial protected areas and ecologically intact landscapes, including boreal and tropical primary forests, savannas and marshes.

The finding does not mean all Indigenous territories are pristine or formally protected. It demonstrates the substantial geographical overlap between Indigenous lands and landscapes that remain important for conservation.

That overlap matters for climate policy as well. Forests, wetlands and other intact ecosystems store carbon while supporting biodiversity and regulating water and other ecological processes.

One-third of Irrecoverable Carbon

The climate significance becomes clearer when carbon is considered.

A 2022 study in Nature Sustainability identified 139.1 gigatonnes of irrecoverable carbon remaining in Earth’s ecosystems, with considerable uncertainty around the estimate. The researchers found that 33.6% of this carbon—46.7 gigatonnes—is within lands managed by Indigenous Peoples and local communities, compared with 23% within protected areas.

“Irrecoverable” carbon refers to ecosystem carbon that, if released, could not be restored by mid-century—the timeframe considered critical for reaching net-zero emissions.

The figure does not mean Indigenous management itself creates these carbon stocks. It shows that a substantial share of carbon that climate policy has strong reason to protect is located within Indigenous and local-community lands.

Knowledge Accumulated Through Generations

Indigenous knowledge adds another dimension. Indigenous and local communities have developed detailed knowledge of species, habitats, seasonal cycles and natural resources through long-term relationships with particular landscapes. Such knowledge can complement scientific monitoring, particularly when environmental changes are observed over long periods.

The important question, however, is not simply whether conservation projects can use this knowledge. It is whether the people who hold it have a meaningful role in decisions affecting their territories.

A 2024 review in One Earth examined this question across conservation research. The researchers reviewed 648 empirical studies and analysed ecological outcomes in a subset of 170 studies. They found that more equitable governance arrangements—where Indigenous Peoples and local communities had equal partnership or primary control—were associated with significantly more positive ecological outcomes.

The study identifies an association, not proof that Indigenous governance automatically produces better results in every ecosystem. Conservation outcomes also depend on local institutions, ecological conditions, economic pressures and enforcement. But the finding challenges a model in which communities are merely consulted after conservation decisions have already been made.

The 30% Target Makes Governance Important

This issue is becoming more relevant as countries work towards the Kunming-Montreal Global Biodiversity Framework’s 30-by-30 target: conserving and effectively managing at least 30% of terrestrial, inland-water, coastal and marine areas by 2030.

The target itself calls for conservation areas to be equitably governed and recognises the rights of Indigenous Peoples and local communities where applicable. That means expanding protected areas cannot be measured only in hectares. How those areas are governed—and who has authority within them—also matters.

Climate Action Can Create New Pressures

The relationship between Indigenous territories and climate policy is not limited to forest conservation. The transition away from fossil fuels requires minerals used in batteries, electricity infrastructure and other technologies. Research published in Nature Sustainability found that more than half of the world’s energy-transition mineral resource base is located on or near the lands of Indigenous and peasant peoples.

This creates a potential contradiction: technologies intended to reduce emissions can generate new pressures on land and communities through mineral extraction.

A credible climate transition therefore has to consider not only the emissions avoided by new technologies, but also where their materials come from and whose territories are affected.

India: Where Forest Rights Meet Conservation

The global evidence has a clear relevance to India, although India’s legal framework generally uses the terms Scheduled Tribes and other traditional forest dwellers rather than the broader international category of Indigenous Peoples. India’s 2011 Census recorded about 104 million Scheduled Tribe people, representing 8.6% of the country’s population.

Forest-dwelling woman in traditional attire collecting resources from a stream, reflecting Indigenous and tribal communities’ relationship with forests in India
A forest-dwelling woman gathers resources from a stream, illustrating the close relationship between India’s tribal communities, forests and natural resources. Representational image. Image credit: masudar rahman/Pexels

The Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006, commonly known as the Forest Rights Act, recognises rights of forest-dwelling Scheduled Tribes and other traditional forest dwellers over forest resources. It also provides for community forest-resource rights, including the right to protect, regenerate, conserve and manage community forest resources. Government data show the continuing scale of implementation.

As of December 31, 2025, the Ministry of Tribal Affairs reported 44,33,940 forest-rights claims had been settled, meaning a decision had been taken. These comprised 42,56,845 individual claims and 1,77,095 community claims. The data cover implementation in 20 states and one Union Territory.

The difference between individual and community claims is significant because community forest rights concern collective relationships with forests and their management. For India, therefore, the conservation question is not simply how much forest can be protected. It is also how communities with established relationships with forests participate in managing them and how their legally recognised rights are implemented.

What the Evidence Tells Us

The research does not justify portraying Indigenous Peoples as universally or inherently sustainable. Their communities, institutions and environmental practices differ widely. The evidence supports a more precise conclusion.

Indigenous Peoples manage or have tenure rights over at least 38 million sq km in the countries covered by the major global mapping study. Their territories intersect about 40% of terrestrial protected areas and ecologically intact landscapes. Indigenous Peoples and local communities manage lands containing 33.6% of the world’s mapped irrecoverable carbon. And a review of 648 conservation studies found that more equitable governance was associated with more positive ecological outcomes.

Together, these findings suggest that Indigenous Peoples should not be viewed simply as beneficiaries of conservation programmes or sources of traditional knowledge. They are already part of the governance of many ecologically important landscapes.

For climate and biodiversity policy, the implication is straightforward: protecting ecosystems can also require protecting the rights, knowledge and decision-making roles of the people who live with them. While that does not replace scientific research or environmental regulation. It expands the evidence and the institutions available to protect nature.

Continue Reading

Climate

From Fighting Water to Saving It: The Netherlands Faces a Growing Drought Challenge

A land built to keep water out is now struggling to keep enough of it in — forcing a world leader in water management to rethink its infrastructure

Sebin Pious

Published

on

Netherlands drought challenge
Low water levels on the Nederrijn near Arnhem's Andrej Sacharovbrug, 5 August 2026. Photo: Tomas Guus / Wikimedia Commons (CC0)

The Netherlands built its global reputation by keeping water out. Now, longer dry spells and intensifying heatwaves are forcing the country to confront a very different problem: how to keep enough fresh water in the landscape. From greenhouse agriculture to homes built on wooden foundation piles, the Netherlands drought challenge is exposing the limits of infrastructure designed primarily for flood protection.

When people think of the Netherlands, the images that come to mind are windmills, tulip fields and the great sea walls that have kept the ocean at bay for centuries. The Dutch built their reputation, and much of their nation, on mastering water — pumping it away, holding it back, and reclaiming land from the sea to build a prosperous country on ground that, by rights, shouldn’t exist. Yet beneath that carefully engineered landscape, the Netherlands is now facing an unfamiliar problem: it is running out of fresh water.

As repeated summer heatwaves sweep across Western Europe, Dutch water authorities say they have reached the limit of what engineering can do. In several regions, officials have exhausted every standard measure available to them and are left with what amounts to a last resort — waiting, and hoping, for rain.

Netherlands Drought Challenge: From Floods to Water Scarcity

To understand how a country famous for its rainfall and rivers has arrived at this point, it helps to look at how the land itself was designed. For generations, the Dutch water system had one job: get excess water out to sea as fast as possible, to prevent flooding. That same efficiency has become a liability as weather patterns shift towards longer dry spells and more intense heat. The pressure peaks in late summer, when temperatures regularly cross 35°C and water evaporates faster than rainfall can replace it.

The consequences of shrinking water reserves go well beyond the daily weather report. They are already reaching into the economy, and into the foundations — quite literally — of Dutch homes.

Thousands of historic Dutch houses stand on wooden foundation piles. When groundwater levels drop, those piles are exposed to air and begin to rot. On clay and peat soils, the ground shrinks unevenly, pulling foundations down and cracking brick walls

Economic Strain and Sinking Homes

In Westland, the heart of Dutch greenhouse horticulture, the Delfland water authority has banned growers from drawing irrigation water from local ditches and canals — the first such ban in its history. According to the growers’ umbrella body Glastuinbouw Nederland, the ban affects around 150 commercial growers, with potential damages running as high as €150 million.

At the same time, a quieter crisis is unfolding beneath people’s homes. Thousands of historic Dutch houses stand on wooden foundation piles. When groundwater levels drop, those piles are exposed to air and begin to rot. On clay and peat soils, the ground shrinks unevenly, pulling foundations down and cracking brick walls. The Council for the Living Environment and Infrastructure estimates that close to half a million buildings across the country could show foundation damage by 2035, with repair costs reaching as much as €54 billion.

From Water Battle to Water Sponge

This reality is forcing a fundamental shift in how the Netherlands manages its resources. For centuries, Dutch policy was simple: fight the water, and push it away. Today, water authorities are engaged in a delicate balancing act, trying to save every drop using canal locks and storage basins. But holding onto existing water can only do so much once the rain stops altogether.

Long-term resilience will require redesigning the landscape itself. Rather than treating rainwater as a threat to be flushed out to sea, experts increasingly argue that the Netherlands needs to function more like a giant sponge — capturing heavy winter rain and storing it safely to survive the dry summer months that are becoming the norm.

A Lesson Beyond Borders

What is unfolding in the Netherlands carries a lesson well beyond it. If a nation this experienced in water engineering is struggling to keep pace with a changing climate, it says something about how quickly conditions can outrun even the most sophisticated infrastructure. As riverbeds stay low and the dry spells drag on, the Dutch find themselves in an unfamiliar position for a country built on water: waiting for the skies to open.

Continue Reading

Trending