By Prof Ajit Tyagi, Honorary Patron & Chairman of the Committee on Climate Change, India Water Foundation
Prof. Ajit Tyagi is Honorary Patron and Chairman Climate Change Committee of India Water Foundation. He has served asDirector General of Meteorology, India Meteorological Department and Assistant Chief of Air Staff (Meteorology), Indian Air Force. He was Permanent Representative of India (2008-12) with World Meteorological Organisation. Prof Tyagi played key role in promoting climate services at the National, Regional and Global level. He as Director General of Meteorology carried our modernisation of India Meteorological Department and brought significant improvements in weather forecasting and warning of high impact weather events in the country.
Climate Change and Ecosystem Restoration
Ecosystem
Ecosystems are the important integral benefits to the society. Healthier ecosystems, yield greater benefits such as more fertile soil, higher farm productivity, bigger yields of timber and fish and larger stores of greenhouse gases. They also provide planet-wide benefits like climate protection and biodiversity conservation. For many people pristine ecosystem plays a powerful spiritual and aesthetic role. The Millennium Ecosystem Assessment (MA 2005) grouped ecosystem services into following four groups:
Provisioning Services (Food, Water, Fuel and Wood/Fiber)
Regulating Services (Climate, Food and Disease, Water Purification) Supporting Services (Soil formation, Nutrient cycling, Primary production
Cultural Services (Educational, Recreational, Aesthetic, Spiritual)
Ecosystems contain biotic or living parts as well as well as nonliving parts an ecosystem is a place where plants, animals and other organisms, in conjunction with the landscape and climatic condition around them, come together to form the web of life. An ecosystem can be as small as a small pond, or as big as an ocean, spanning thousands of kilometers. Broadly ecosystems fall in two categories i.e Terrestrial Ecosystem and Aquatic Ecosystem. Recently Urban Ecosystem has also been added. There are different type of terrestrial ecosystems distributed around various geological zones. These are: 1. Forest Ecosystem, 2. Grassland Ecosystem, 3. Tundra Ecosystem and 4, Desert Ecosystem. Aquatic ecosystem is of two types: 1. Freshwater Ecosystems and 2. Marine Ecosystem
Climate and Ecosystem
Ecosystems are controlled both by external and internal factors. External factors, also called stated factors, control the overall structure of an ecosystem. The most important of these is climate. Climate determines the biome in which the ecosystem is embedded. Rainfall patterns and seasonal temperatures influence photosynthesis and thereby determine the amount of water and energy available to ecosystem.
Changing climate affects ecosystem in variety of ways. Warming may force species to migrate to higher latitudes or higher elevations where temperature is more conducive to their survival. Similarly, as sea level rises, saltwater intrusion into a fresh water system may force some species to relocate or die.
Ecosystem degradation
In the last two centuries, industrialization and exponential growth of population has led to increasing demand on ecosystem resources. In the recent decades environmental impacts of anthropogenic actions are becoming significant. Common features responsible for causing degradation of all types of ecosystems are climate change, environmental pollution, unsustainable exploitation of natural resources and loss of biodiversity. Humanity’s hunger for resources has pushed many ecosystems to the breaking point1. Figure 1 shows processes involved in ecosystem degradation. As per world Economic Forum, around 1.9 million square kilometers of undisturbed ecosystems have been lost between 2000 for and 2013. The area of primary forest worldwide has deceased by over 80 million hectares since 1990 as per Food and Agriculture Organisation. Soil erosion and other forms of degradation are costing the world more than $6 trillion in lost food! production and other ecosystem services. Approximately 30% of natural freshwater ecosystems have disappeared since 1970 (UNEP 2021)2. Habitatdegradation is endangering animal species.
Ecosystem/Land degradation and climate change, both individually and combination, have profound implications for natural resource-based livelihood systems and societal groups as per IPCC Report3.
Climate Change
The Earth’s climate has changed throughout history. In the last 650,000 years, there have been seen cycles of glacial advance and retreat, with an abrupt end of last ice age about 11,000 years ago. It marked the beginning of the modern climate era and of human civilization. Most of these climate changes are attributed to very small variation in Earth’s orbit that change the amount of solar energy received by the Earth. These climate changes used to take place over a very long period spread over thousands of years. The current warming trend is of significance because most of it is caused by human activity since the mid-20th century and proceeding at a rate unprecedented.
Annual Report on State of Global Climate 2020 by the World Meteorological Organisation confirms relentless, continuing climate change, an increasing occurrence and intensification of high-impact events and severe losses and damages affecting people, societies and economies4.
Concentrations of the major greenhouse gases continued to increase in 2019 and 2020. Globally averaged mole fractions of carbon dioxide (CO2) have already exceeded 410 parts per million (ppm), and if the CO2 concentration follows the same pattern as in previous years, it could reach or exceed 414 ppm in 2021. Methane (CH4) was at 1 877 ± 2 parts per billion (ppb) and nitrous oxide (N2O) at 332.0 ± 0.1 ppb, respectively, 148%, 260% and 123% of pre-industrial (before 1750) levels.
The global mean temperature for 2020 was 1.2 ± 0.1 °C above the 1850–1900 baseline (Figure 1), which places 2020 as one of the three warmest years on record globally. The past six years, 2015–2020, were the six warmest on record. The last five-year (2016–2020) and 10-year (2011–2020) averages were also the warmest on record.
The majority of the excess energy that accumulates in the Earth system due to increasing concentrations of greenhouse gases is taken up by the ocean. The added energy warms the ocean, and the consequent thermal expansion of the water leads to sea-level rise, which is further increased by melting ice. The surface of the ocean warms more rapidly than the interior, and this can be seen in the rise of the global mean temperature and in the increased incidence of marine heatwaves. As the concentration of CO2 in the atmosphere rises, so too does the concentration of CO2 in the oceans. This affects ocean chemistry, lowering the average pH of the water, a process known as ocean acidification. All these changes have a broad range of impacts in the open ocean and coastal areas. All data sets agree that ocean warming rates show a particularly strong increase over the past two decades. Moreover, there is a clear indication that heat sequestration into the ocean below 700 m depth has occurred over the past six decades and is linked to an increase in OHC trends over time
The ocean absorbs around 23% of the annual emissions of anthropogenic CO2 into the atmosphere, thereby helping to alleviate the impacts of climate change. However, the CO2 reacts with seawater, lowering its pH. This process, known as ocean acidification, affects many organisms and ecosystem services, threatening food security by endangering fisheries and aquaculture. This is particularly a problem in the polar oceans. It also affects coastal protection by weakening coral reefs, which shield coastlines. As the pH of the ocean declines, its capacity to absorb CO2 from the atmosphere decreases, diminishing the ocean’s capacity to moderate climate change. Regular global observations and measurements of ocean pH are needed to improve the understanding of the consequences of its variations, enable modelling and prediction of change and variability, and help inform mitigation and adaptation strategies.
On average, since early 1993, the altimetry-based global mean rate of sea-level rise has amounted to 3.3 ± 0.3 mm/yr. The rate has also increased over that time. A greater loss of ice mass from the ice sheets is the main cause of the accelerated rise in global mean sea level.19Global mean sea level continued to rise in 2020
Next to oceans, cryosphere is a major indicator of the state od climate. Cryosphere comprises the frozen part of the earth. Sea-ice extent, glacier mas balance, mass balance of Greenland and Antarctic ice sheets are major cryosphere indicators.
The Arctic has been undergoing drastic changes as the global temperature has increased. Since the mid-1980s, Arctic surface air temperatures have warmed at least twice as fast as the global average, while sea ice, the Greenland ice sheet and glaciers have declined over the same period and permafrost temperatures have increased. This has potentially large implications not only for Arctic ecosystems, but also for the global climate through various feedbacks.
In 2020, the Arctic stood out as the region with the largest temperature deviations from the long-term average. Contrasting conditions of ice, heat and wildfires were seen in the eastern and western Arctic
Annual precipitation totals in monsoon-influenced regions in North America, Africa, South-West Asia and South-East Asia were unusually high in 2020, as were extreme daily totals. The African Monsoon extended farther north into the Sahel region than usual. Monsoon seasonal totals in India were 109% of the long-term mean, the third highest seasonal total after 1994 and 2019. East Asia experienced abnormally high annual and extreme daily rainfall totals.
Observations of climatic indicators show that Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen.
Extreme Weather events cause disruption in ecosystems. Very extensive flooding occurred over large parts of Africa in 2020. India had one of the two wettest monsoon seasons since 1994, with nationally averaged rainfall for June to September 9% above the long-term average. More than 2000 deaths were reported during monsoon season in India, Pakistan, Nepal, Bangladesh, Afghanistan and Myanmar. Severe drought affected many parts of South America with the worst affected areas being northern Argentina, Uruguay, Paraguay and western Brazil. The year was an exceptionally warm year for most of Russia, especially Siberia. Verkhoyansk in Siberia recorded 38.00 C on 20 June, provisionally the highest known temperature anywhere north of Arctic circle4. Finland set new national highest temperature records in 2020. Summer was very hot in parts of East Asia.
A number of exceptionally large wildfires were recorded in California and Colorado in the US and eastern Australia. The number of tropical cyclones globally was above average in 2020, with 98 named tropical storms Cyclone Amphan which made landfall on 20 May near India-Bangladesh border in the was the costliest tropical cyclone for the North Indian Ocean, with reported economic losses in India approximately US$ 14 billion4.
Impact of Climate Change
Climate change has serious implication for ecosystem services and biodiversity. Climate stressors are already having adverse impact on ecosystems. Projected climate change will exacerbate adverse impacts. Warming will lead to change in the distribution of terrestrial ecosystems as plants and animals follow the shifting climate. In the mountainous regions species and ecosystems will migrate up mountain slopes from lower elevations.
Climate change will have negative impact on terrestrial ecosystems caused by increased frequency and severity of droughts, wildfires in forest and peatland areas, land degradation, sand and dust storms, and desertification. In freshwater systems, impacts include floods and water stress, and in marine systems, they include sea-level rise, ocean acidification, reduced levels of ocean oxygen, mangrove decay and coral bleaching. Many of these impacts are linked to biodiversity loss. For example, besides the heavy human impacts of the wildfires in Australia in 2019 and early 2020, there was likely a severe loss or displacement of many millions of animals during the disaster.
There are already indications of dramatic impacts of global warming at the system level, particularly in the arctic and for coral reef systems. Mass coral bleaching driven by warmer sea temperatures has killed vast numbers of corals across the tropics, causing some reefs to lose their ecosystem structure and functions5. Six major coral bleaching events have occurred across the world since 1979, when they first were reported in the scientific literature.
The 2030 Agenda for Sustainable Development provides a shared blueprint for peace and prosperity for people and the planet, now and into the future. At its heart is a set of sustainable development goals (SDGs), which recognize that ending poverty and other deprivations must go hand-in-hand with strategies that improve health and education, reduce inequality, and spur economic growth, while tackling climate change and preserving oceans and forests. The achievement of many of these goals is put at risk by climate change, however. For example, rising temperatures are leading to the loss of species and ecosystems, which can reduce agricultural and fishing yields, contributing to food insecurity and affecting livelihoods (SDGs 1, 2, 14 and 15). Extreme weather and climate events can increase health risks, damage infrastructure and lead to water scarcity (SDGs 1, 3, 6, 9 and 11). These threats, together with others, are interrelated with conflict and stability (SDG 16). Uneven distribution of such risks across populations and regions can reinforce or worsen existing inequalities (SDG 10).
Figure 3 demonstrates how rising atmospheric CO2 concentrations lead to cascading effects via six of the other key climate indicators. Beyond posing risks to achieving sustainable development, some of these processes also have the potential to release further greenhouse gases into the atmosphere in a feedback loop that can perpetuate warming. For example, rising temperatures can thaw permafrost, releasing more carbon into the atmosphere.
Recent studies indicate that rapidly rising greenhouse gas concentrations are driving ocean systems toward conditions not seen for millions of years, with an associated risk of fundamental and irreversible ecological transformation. The impacts of anthropogenic climate change so far include decreased ocean productivity, altered food web dynamics, reduced abundance of habitat-forming species, shifting species distributions, and a greater incidence of disease. Although there is considerable uncertainty about the spatial and temporal details, climate change is clearly and fundamentally altering ocean ecosystems. Further change will continue to create enormous challenges and costs for societies worldwide, particularly those in developing countries.
Ecosystem Restoration
Ecosystem restoration means assisting in the recovery of ecosystems that have been degraded or destroyed, as well as conserving the ecosystems that are still intact. The climate change is happening at an unprecedented rate and impacting a lot of people across the globe [1]. The need for adaptation efforts has never been so urgent. The rising sea levels, longer and more frequent droughts, heightened hurricane activity and floods are increasingly affecting ecosystems. Climate change crisis provides an opportunity to take up ecosystem restoration on priority. The UN has designated the 2020s as the Decade of Ecosystem Restoration. It is a joint initiative of UNEP and FAO of the United Nations calling for the protection and revival of ecosystems all around the world for the benefits of people and nature9.
UN has planned restoration of 350 million hectares of degraded terrestrial and aquatic ecosystems. Restoration could generate US$9 trillion in ecosystem services and also remove 13 to 26 gigatons of greenhouse gases from the atmosphere. The economic benefits of such interventions exceed nine times the cost of investment whereas inaction is at least three times more costly than ecosystem restoration. Restoring ecosystems large or small protects and improves livelihood.
Of various approaches for ecosystem restoration Nature based Solutions (NbS)/Ecosystem based Adaptation (EbA) is found to be favorite as it provides a lasting and sustainable set of solutions in a cost-effective manner to cope with climate change and sustainable development challenges, especially when used in combination with other methods and approaches1,7,8.
Ecosystem based approaches to adaptation harness the capacity of nature to buffer human communities against the adverse impacts of climate change through the sustainable delivery of ecosystems services. Deployed with focus on specific ecosystem services with the potential to reduce climate change exposures, the forms used are targeted management, conservation and restoration activities. For example, mangrove forest and coastal marshes buffer storm surges energy and research and practical work have shown that restoring or conserving mangrove ecosystems can therefore help protect coastal communities from current and projected rise in the number of tropical storms due to the changing climate. Ecosystems deliver services that can help meet adaptation needs across multiple human development sectors including disaster risk reduction (through fold regulation and storm surge protection), food security (from fisheries to agro-forestry), sustainable water management and livelihood diversification (through increasing resource-used options). EbA can also generate significant multiple benefits such as carbon sequestration and other social, economic and cultural benefits. Healthy ecosystems and their services provide opportunities for sustainable economic prosperity while providing defense against the negative effects of change (Figure 4).
The main advantages that EbA has over others adaptation approaches are that it can deliver multiple co-benefits, it can help avoid maladaon and contributes to a ‘no regrets’ approach to address climate change. EbAachieves multiple policy objectivesforsociety and the environment in the face of climate change by providing: A win for climate change adaptation and mitigation. A win for socio-economic development. A win for the environmental protection and biodiversity conservation. A win for contributing to sustainable economic development. EbA provides a lasting and sustainable set of solutions in a cost-effective manner to cope with climate change and sustainable development challenges, especially when used in combination with other methods and approaches.
In 2020, IUCN has come up with NbS Global Standard and reliably design, assess and o enable everyone to consistently and reliably design and scale up Nature based Solutions. Governments, Private Sector, NGOs and others can use IUCN Global Standard to consistently design effective NbS Projects that are ambitious in scale and sustainability and thus will help on Ecosystem restoration9. UN Decade of Ecosystem Restoration provides a platform for transformational ecosystem restoration by active participation of countries, the international community, civil society, the private sector and other stakeholders10.
References
- Richard Munang, Ibrahim Thiaw, Keith Alverson, Musonda Mumba, Jian Liu and Mike Rivington (2013), Climate change and Ecosystem-based Adaptation: a new pragmatic approach to buffering climate change impacts: http//dx.doi.org/10.1016/j.cosust/2012.12.001
- www.worldenvironmentday.global
- www.ipcc.cht
- The State of the Global Climate 2020 (2021), public.wmo.in
- Hoegh-Guldberg O (1999): Climate change, coral bleaching and the future of the world’s coral reefs. Marine and Freshwater Research, 50:8
- www.decadeonrestoration.org
- www.iucn.org/resources/issues-briefs/ecosystem-based-adaptation
- www.unep.org
- www.ser.org
- IUCN Global Standards for IUCN (2020) www.iucn.org
