A Solution to Climate Crisis
It seems the nature is finding it harder and harder to tolerate human encroachments. From intensified hurricanes to ravaging wildfires, from dwindling water supplies and ocean acidification to growing desertification, from rapid extinction of flora and fauna to melting of the permafrost; nature is using all weapons in its arsenal to warn the humans that they are treading the path to self-destruction. Earth Overshoot Day is one such indicator that points to unsustainable, destructive and wasteful relationship we have with nature. It is a day in a given year when humanity’s demands for renewable ecological resources and services exceed what the Earth can regenerate. In 1987, when scientists began calculating the Earth Overshoot Day, October 3 was the estimated day when humans overshot the planetary budget. In 2020, this day fell on August 22 – in other words, humans have decreased the capacity of the Earth to regenerate resources by 66 days within 33 years. This ecological deficit is expected to further widen in the next decades with debilitating ecological, economic, social and health-related impacts. The gravity of the situation can be gauged from the fact that 83 percent of the Earth is facing the deleterious impacts of human activities. At this current rate, we are on the path to exhausting irreversibly the capacity of the Earth to provide sustenance for our survival. The growing human footprint and its repercussions in the disruption of the global atmospheric and ocean circulations have convinced scientists that the only sustainable remedy to climate crisis is the restoration of ecosystems which has emerged as one of the most important pillars of anti-climate change plans that are being implemented vigorously to tackle this global crisis.
An ecosystem, simply speaking, is an interaction between biotic factors (animals, plants, microorganisms, etc.) and abiotic factors (land, soil, water, air, rocks, sunlight, etc.). This interacting community of living and non-living objects gives rise to complex processes and services which are vital for survival of humans and other species. Various ecosystems provide critical supporting, cultural, regulating and provisioning services. Regulating services include air purification, water filtration, decomposition of dead bodies of animals and plants, pollination, flood and erosion control, carbon sequestration and pest regulation. Ecosystems offer cultural services in the form of recreational, educational, spiritual and tourism-related facilities. As regards provisioning services, food and timber production, availability of drinking water and fossil fuels and plants and their medicinal products are some worth-mentioning among them. Supporting role of ecosystems is the most important as services in this domain provide the bedrock for other services. Photosynthesis, nutrient cycle (carbon and nitrogen cycles), soil formation and hydrological cycles are a few vital processes that are essential for human survival on Earth. As per a paper published in ‘The Journal of Global Environmental Change’, the estimated total value of the ecosystem services is worth $124.8 trillion which is 1.4 times higher than the average global value of GDP in 2019. Climate change which is creating existential threats for humans is also impacting the ecosystems and their ability to provide services. During the last 50 years or so, especially after the Great Acceleration in the wake of the Second World War, human activities have changed ecosystems more rapidly and extensively than any comparable period in human history.
Change in thermal regime is one such impact of climate change that is constraining the ability of ecosystems to provide provisioning and supporting services. It has been estimated that the habitable zone for both animals and plants is shifting towards higher latitude and altitude. This rate of shift has been determined 36 feet per decade towards elevation, and for latitude, it is 16.9 km per decade. At some regional level, this pole-ward movement of suitable climate zone, which is called Climate Change Velocity, has been calculated as 20km per year as opposed to 0.002km per year of that for the last 20,000 years – too fast for many species to adapt to. Resultantly, species are facing extinction due to habitat destruction, productivity loss and disturbances in natural events. This range shift is impacting the growth and survival particularly of the species which already reside at mountain tops or the northern limit of habitable land. The 30° isotherm (the line that joins parts of the country that have the same temperature) of Pakistan has also shifted 725m towards higher elevation (Pakistan Journal of Meteorology) which points to a shift in the range of the habitable zone. This shift in heat from lower elevation to higher elevation is bound to cause rapid melting of glaciers in northern areas and frequent heatwaves in southern areas. It can also impact the yield of major crops in the grain baskets of Pakistan – Punjab and Sindh – which, in return, would threaten the food and nutrition security of millions of people.
Disruption in the food web or the relation between prey and its multiple predators is also a climate change-driven phenomenon. Extinction of one species causes a ripple effect down to the level of decomposers (bacteria, fungi, etc.). Disruption in the food web or chain causes further extinction of species, imbalance in natural phenomena, loss of biodiversity and even conflicts and wars.
Intensification of the hydrological cycle is another pronounced impact of climate change. The winters are increasingly becoming milder and shorter resulting in the increased stream discharge which is responsible for leaching losses of nitrogen and phosphorous. The leaching resultantly causes a reduction in the soil fertility of upland terrestrial ecosystems and leads to the problem of eutrophication and algal blooms in downstream streams, lakes and coastal areas. Eutrophication, in return, shrinks oxygen level in water and both freshwater and marine ecosystems, consequently, face the death of aquatic life.
Global warming is also causing thermal stratification of oceans which prevents the upwelling of nutrients from the deep sea. The unavailability of nutrients is largely responsible for a one percent per year reduction in the primary productivity (fishing etc.) of 8 out of 10 of the major ocean basins of the world.
In view of the impacts of climate change on the various ecosystems and the resultant economic and ecological losses, the world has increasingly realized the criticality of ecosystem restoration as the solution to climate change, in tandem with other economic, legal and administrative measures. This restoration is supporting the recovery of ecosystems’ functions, structure and services through nature-based initiatives and interventions. The international community is aiming at restoring 350 million hectares of degraded terrestrial and aquatic ecosystems by 2030 which is bound to yield multiple economic, ecological and health-related dividends. Most importantly, ecosystem restoration would help strengthen the fight against climate change.
In the following paragraphs, various kinds of ecosystems and their role in countering climate change have been discussed.
Wetland ecosystem or land consisting of marshes or swamps or any saturated land is one of the most important kinds of ecosystems that can play a critical role in climate adaptation and mitigation. They cover almost six percent of the land surface and offer $15 trillion worth of economic dividends globally.
Wetland ecosystems are further divided into two classes: inland wetland (flood plains, rivers, lakes and swamps), and coastal wetland (mangroves, salt marshes, seagrass beds and coral reefs). Inland wetlands absorb excessive rainfall and reduce flood surges, thereby preventing soil erosion downstream. They provide refuge to wildlife and recharge the underground water table. Coastal wetlands reduce the velocity of waves and thus prevent or slow down the storm surge. Roots of wetland plants stabilize the shoreline and stop erosion. The most important ecological function of wetlands is carbon sequestration. They are estimated to store one-third of the world’s terrestrial carbon. The UN General Assembly once termed wetland ecosystem as “Blue Carbon Ecosystem” and acknowledged its role as the low-cost method of climate adaptation. Ramsar Convention, which came into force in 1975, deals with the conservation of wetland. It binds signatories to undertake conservation and protection measures. Wetlands’ ability to reduce GHG emissions through sequestrating them in wetland soil, peat, litter and vegetation has made them an important source for climate mitigation as well. They allow rapid vegetative growth and have improved hydrology which makes any wetland restoration effort a hugely successful endeavour. Pakistan has 122 wetland ecosystems with a total area of 1.3 million hectares and 19 Ramsar Sites which include mangroves, delta marshes, flood plains and artificial dam lakes. Increasing temperature, unpredictable and changing precipitation patterns and human encroachment are depriving Pakistan of such an important carbon sink that warrants sustainable wetland management through capacity building of institutes and protecting Ramsar Sites from human encroachment and activities.
A watershed ecosystem can also play an important role in adaptation and, to some extent, in mitigation of climate change. The watershed is an area of land and water bounded by a drainage divide where surface water runoff, generated by rainfall or glacier melt, collects and flows into a single outlet (river, lake, dam or pond, etc.) In other words, the watershed is an entire geographical area that is drained by a single river and its tributaries. A group of watersheds is termed a river basin. Gilgit-Baltistan is Pakistan’s largest watershed area that supplies water to the Indus River which is a lifeline for Pakistan’s economy and food security. Like other ecosystems, watershed areas are also bearing the brunt of climate change in the forms of accelerated water erosion due to floods, the demise of flora and fauna, biome shift and increased temperature. Different watershed management practices including constructions of check dams, terracing, afforestation, restoration of natural water pathways, soil stabilization would go a long way in strengthening the resilience of watershed communities. In addition, watershed management is bound to reduce sedimentation in the rivers, improve the quality of water particularly for eco-services, streamline the recharge of groundwater, ensure perennial stream flow, and improve the life of downstream infrastructure like dams, barrages, canals, and, most importantly, it can reinforce the community’s resilience against climate change-induced threats like Glacial Lake Outburst Floods(GLOF’s).
Scrubland or shrubland or desert ecosystem can potentially play a significant role in storing carbon and thereby reducing GHGs. Pakistan has a huge scrubland forest which consists of low-yielding thorny vegetation that occupies the Pothwar region including the Salt Range. They are facing rapid degradation due to increasing temperature and unpredictable rainfall patterns. Restoration of the scrubland-based ecosystem can help improve air and water quality, enhance wildlife habitat and biodiversity conservation. Hot and cold desert shrublands like Indus deserts (Thal, Thar and Cholistan) and Katpana desert in Skardu are also a good choice for ecosystem restoration for accelerated climate change mitigation. Shrubs offer huge opportunities for carbon storage because of their deep root system and standing biomass resultantly, the restoration of adaptive indigenous vegetation will not only reduce GHGs, but will also help check the desertification by stabilization of dunes. Plantation of exotic species in these areas are not worth investment as water scarcity would enhance the cost of afforestation and would disturb the natural ecological balance, therefore, restoration of indigenous species through direct seeding or other methods must be pursued for ensuring nature-based climate change mitigation.
Restoration of the degraded marine ecosystem is another cost-effective and viable low-tech remedy to climate change. Oceans cover 71% of the total surface area of planet Earth and support oceanic circulation which is vital for temperature regulation at global and regional levels. Any disturbance in the acidity, salinity, heat capacity of the water or oxygen level is bound to create crippling consequences for coastal community resilience and resistance against climate change. Management of the marine ecosystems can pave the way for the resolution of the climate change-induced problems of acidification, sea-level rise, shifts in species distribution, and decrease in productivity and oxygen availability. A healthy ecosystem can help expedite carbon sequestration, buffer against environmental fluctuation, and moderate extreme events like tsunamis, hurricanes and tornadoes. Pakistan enjoys extensive coastal and marine ecosystems. We have a 1046-km-long coastline and an Exclusive Economic Zone with an area of 240,000km2 along with a continental shelf that extends up to 350 nautical miles. Our potential for blue economy is almost untapped but it offers a unique opportunity for sustainable utilization of marine resources. In this regard, the establishment of effectively-managed and ecologically-represented Marine Protected Areas is one such remedy that can help improve the eco-services of our marine resources. Despite the designation of four sites by the Ministry of Climate Change as potential MPAs, Pakistan has only one IUCN-approved marine protected area: Astola Island. Pakistan needs a declaration of at least 10% of its marine area as MPAs for meeting the UN SDG 14 which calls for conservation and sustainable use of oceans, seas and marine resources for sustainable development. Potential sites for MPAs designations are Churna Island, Gwadar Bay (trans-boundary bay straddling Pakistan and Iran border), Indus Swatch (the inundated canyon at the point of Indus delta which is the world’s second-largest submarine fan) and Miani Hor (a lagoon along the coast of Balochistan). All these sites provide habitat for various marine species and can be developed as sites for tourism and other allied economic activities of the blue economy.
The incumbent government – though it can be criticized for governance failure – must be given credit for elevating climate management to the highest public policy level. Ecosystem restoration is being pursued vigorously through multiple initiatives such as Ten Billion Tree Tsunami Project, Billion Tree Honey Initiative and Protected Area Initiatives under which 12 national parks in the country are being established. Through this climate activism, Pakistan has emerged as a global leader and is going to hold World Environment Day this year on June 5. Pakistan has also been elected as a member of the prestigious Green Climate Fund which will help us greatly in approving funds for climate mitigation and adaptation under Paris Agreement mechanism. One can hope that during Prime Minister Imran Khan’s government, who is himself an avid environmentalist, Pakistan would continue to take various statutory, administrative, and ecological interventions for a sustainable environment for our next generations.
With the passage of every day, it is gradually becoming obvious that preventing the global temperature from crossing the ceiling of 2°C by the end of this century is an impossible task. An annual reduction of 7.6% in GHGs is too high a price for developing countries to accept. The reduction through de-carbonization of economic activities does not seem economically feasible, the only way forward is a reduction in GHGs through the nature-based solution that is restoration of ecosystems. Restoration can also create economic dividends as well. In the words of Malik Amin, SAPM on climate change, ecosystem restoration efforts alone could generate $9trillion worth of economic benefits in the ecosystem services and eliminate 13 to 26 gigatonnes of GHGs from the atmosphere. Conservation of biodiversity, protection of ecological services and goods, and gradual shifting to the green economy can only help the world cope with the devastating impacts of the climate crisis.
The writer is a graduate of the
University of Agriculture, Faisalabad.
He writes on national and international affairs.