The Himalayan Great Thaw

A little bit of history to begin with: The Pleistocene Epoch, also referred to as the ‘Ice Age’ is a period that started around 2.6 million years ago and lasted until around 11,000 years ago. This was the time when extensive ice sheets, ice caps, large lakes and glaciers were formed repeatedly on landmasses with about 30% of Earth’s land area covered in ice.

As temperatures began to rise, the planet altered between glacial and interglacial (warmer) periods with fluctuations in sea levels. We are currently in a warmer interglacial period called the ‘Holocene Epoch’ where frozen ground is thawing at an accelerated rate and referred to as ‘Permafrost Melt’.

What is Permafrost ? The soil that remained frozen year-round over the millions of years came to be known as permafrost. These permanently frozen grounds are most common in regions with high mountains and in Earth’s higher latitudes—near the North and South Poles and lies deep beneath nine million square miles of Earth’s surface. Russia has the world’s largest share: two-thirds of the country’s area sits on permafrost. In the Asian sub-continent, the Hindu Kush Himalaya (HKH) mountain ranges spanning across 8 countries: Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan have extensive permafrost and glacial covers and the melting of this ice due to global warming is a critical topic to address.

What happens when permafrost melts ? Think about food in a refrigerator when there is a power cut for a longer period. Food gets spoilt and freezer items start to thaw and emits smelly gases. This is exactly what happens when permafrost melts. Deep inside the frozen earth are remains of dead plants and animals and as the ice thaws, microbes in the soil awaken and thrive on the defrosting biomass. This microbial digestion releases carbon dioxide and methane and is an alarming scenario as warmer conditions results in more carbon emitted out into the atmosphere. An increase in the amount of carbon dioxide creates an overabundance of greenhouse gases that trap additional heat. This trapped heat leads to melting of glaciers, increases risk of dangerous glacial lake outburst floods, rising ocean levels, which in turn cause flooding.

The Third Pole: The Hindu Kush Himalaya (HKH) is one of the greatest mountain systems in the world, covering 4.2 million sq km and home to the world’s highest peaks. It contains the largest area of permanent ice cover outside of the north and south poles and referred to as the ‘Third Pole’ and has:

• Nearly 1.9 billion people depending on HKH for water, food, and energy
• Source of 10 major Asian river systems and called the ‘water tower of Asia’
• High biodiversity: 330 important bird and diversity areas documented and crucial to protect (because we have already lost 70-80% of biodiversity hotspots relative to 1500AD)
• Approximately 35% of the world population benefits indirectly from HKH resources and ecosystem services

Permafrost warming in the HKH regions has resulted in reduced ground stability, increased occurrences of rockfall, and outburst of glacier lakes. Even if we manage to limit global warming to around 1.5 degree Celsius, it is projected that glacier volumes would decline substantially under current green-house gases emission scenarios that may result in the complete disappearance of glacier mass in the coming decades.

What are the current gaps?

• More research is needed with international cooperation: The HKH region has a complex topography covering eight countries and hence consolidated snow data prior to year 2000 is unavailable. Satellite imagery is required to build out climate models and re-construct snow cover both historical and for predicting future trends with long-term snow course monitoring sites, data collection and the development of cryosphere-related hazard warning systems.
• Increased focus on water governance: India, Bangladesh, Pakistan, and China together account for more than 50% of the world’s groundwater withdrawals. These withdrawals mostly take place in the plains of river basins that originate in the HKH. Groundwater is used mostly for irrigation and in other sectors like urban water provisioning. The eight countries that share the Himalayas have poor government cooperation in terms of knowledge sharing as well as recurring geopolitical standoffs. Increased collaboration at local levels and formal collaboration at state, national and country levels can help ensure water security.
• Restore nature to order by allowing grasslands to reappear: During the ice-age, these regions were covered by grasslands which acted as a safety net for the permafrost. The HKH has numerous examples of good practices in conservation and restoration of degraded habitats that go together with community development. These practices need to be scaled up and scaled out. Rewilding and reforestation practices can help restore nature to earlier times.

In Conclusion:

Imagine a hypothetical scenario where temperatures on earth move to an extreme of the ‘Ice Age’ where the global average was colder by 10 degrees. In this case, life will cease to exist as it would be too frozen to live. Now fast forward to the 20^th century, we are almost 2 degrees warmer, with accelerated glacier melts and ocean levels rising.

Visualizing a worse-case scenario of getting to 5 degrees warmer, would be catastrophic as permafrost melt would be irreversible leading to cities and societies falling apart, risking our entire humanity and future generations. Neither the ‘Ice Age’ or a ‘Scorched Age’ is an answer as we try hit middle ground for an inclusive, species and habitat focused approach for our mere existence.