Due to its geographical and natural diversity, Indonesia is one of the countries most susceptible to the impacts of climate change. This is supported by the fact that Jakarta has been listed as the world's most vulnerable city, regarding climate change. It is also a major contributor as of the countries that has contributed most to greenhouse gas emissions due to its high rate of deforestation and reliance on coal power.
Made up of more than 17,000 islands and with a long coastline, Indonesia stands particularly vulnerable to the effects of rising sea levels and extreme weather events such as floods, droughts, and storms. Its vast areas of tropical forests are vital in balancing out climate change by taking in carbon dioxide from the atmosphere. Projected impacts on Indonesia's agricultural sector, national economy and health are also significant issues.
Indonesia has committed to reducing its emissions within the framework of the Copenhagen Accord and Paris Agreement. Despite the significant impacts of climate change on the country, surveys show that Indonesia has a high proportion of climate change deniers.
Greenhouse gas emissions
Indonesia is one of the world's largest emitters of greenhouse gases due to its large deforestation and forest degradation. Since 2010, Indonesia has been actively involved in the REDD+ program (Reducing Emissions from Deforestation and Forest Degradation), which incentivizes developing countries to reduce deforestation and forest degradation to lower their greenhouse gas emissions. The country strives to achieve these goals by collaborating with national and local stakeholders, setting up a monitoring system to track emissions and forest cover, and integrating policies and institutional frameworks. Not only does this REDD+ program reduce Indonesia's greenhouse gas emissions, but it also protects biodiversity and benefits local communities. While the program looks promising for the future, its implementation in Indonesia is hindered by various obstacles, such as poor governance and institutional capacity, insufficient funding, and tenure issues. Apart from REDD+, Indonesia has the potential to leverage other forest-based climate change mitigation measures such as sustainable forest management and agroforestry. This is important because it ensures that forests are managed in a way that balances economic, social, and environmental objectives. They do this by promoting the conservation and sustainable use of forest resources while also maintaining their carbon stocks.
Despite the goal of reducing greenhouse gas emissions by 29% by the end of 2030, Indonesia has made little progress in reducing emissions in recent years. This can be traced back to the lack of financial support, prevalence of coal-fired power plants, and ongoing deforestation. From 2014 to 2019, Indonesia's emissions increased by 2.2%. To counter all these challenges, the Indonesian government aims to increase the use of renewable energy sources and try to phase out coal. In order to achieve this, there is a need for more concrete action and effective policies to address greenhouse gas emissions.
Impacts on the natural environment
Temperature and climate change projections Indonesia is almost entirely dominated by a tropical climate with air humidities of up to 90% and hot average temperatures of 28 °C in warmer areas. Precipitation mainly exists in low areas and regions of higher altitudes with cold temperatures. During the El Niño, there is less precipitation and during La Niña events, there are more rainfalls. The climate can be divided into wet seasons from November to April and dry seasons from May to October.
According to climate projections, the average temperatures will rise by 1.6 °C by the year 2050 and by 3.9 °C by 2100 under a high-emissions scenario with no limitations in greenhouse gas emissions. Precipitation estimates are largely complex under all scenarios because of the diverse regional patterns that can be found throughout the country.
It is estimated that, under a high-emissions scenario centered at 2050 with respect to the reference time frame 1985–2014, there will be around 8% longer heatwaves with an increase of 98% in heatwave frequency which entails more extreme weather events like droughts and increased runoff processes leading to flooding and other destructive processes.
Marine ecosystems As Indonesia forms the largest archipelago in the world, marine environments are of high importance for the livelihoods and food security of millions of people. With changing climate trends, these ecosystems are gravely impacted.
Oceanic warming and enrichment in CO2 concentrations due to higher greenhouse gas contents in the atmosphere affect the health of coral reef areas and can lead to bleaching and the ultimately the death of the ecosystem. This in turn affects the health, diversity and abundance of species in that whole area and indirectly connected marine parts of the country. Not only does the acidification of the sea water cause lasting harm to the coral reefs through bleaching but it also triggers declines in plankton abundance in general. This causes a change of balance in the entire food web since plankton serves as a food source for a variety of marine organisms.
Due to the increased incidence of extreme weather events such as storms and typhoons predicted for the future climate, vulnerable marine environments like coral reefs will experience further damage.
Rises in sea levels already are particularly challenging for Indonesia. Estimates show that around 42 million people living less than 10 meters above sea level are menaced. This will have effects like coastal erosion, flooding and loss of habitats crucial for biodiversity like mangrove forests which create breeding grounds for fish and a high number of other marine species. If these areas of high biodiversity decrease in size and abundance, fish populations will decline.
Increased temperatures coupled with changing climatic conditions may have negative impacts on ocean currents and the distribution of fish populations, creating fluctuations in the availability and distribution of stocks. This causes imbalances in the food web system.
Terrestrial environment
The impact of climate change upon the terrestrial environment of Indonesia is varied. Indonesia has one of the highest rates of deforestation in the world, much of which is driven by agricultural and logging industries. A study in 2022 estimated that the emissions impact from deforestation fires in Indonesia and Brazil was 3.7 (±0.4) and 1.9 (±0.2) Gt CO2eq in 2019 and 2020, respectively. Consequently, Indonesia's terrestrial environment has suffered from land changes, deforestation, changes to the groundwater table, reduction in biodiversity and ecosystem structural changes. An increase in extreme weather events due to climate change, notably forest fires in Indonesia have further contributed to the emission of greenhouse gas emissions.
The estimated anthropogenic effects upon bioregions have been measured using the Human Footprint analysis. Human footprint is a measure of pressures from human populations, transportation infrastructure, housing and land transformations upon the integrity of natural systems and environments. Between 2012 and 2017, the human footprint of all bioregions within national parks and in a 10 km buffer area outside the park were reported to have increased in Indonesia.
Around 2.2 million Ha of degraded forests exists within 'protected areas' in Indonesia, accounting for about 10% of total protected areas. The majority of peatlands in Indonesia have been subject to logging, agricultural expansion and plantation resulting in the drainage of peat. The drainage of peatlands are associated with increases in erosion, release of carbon dioxide due to exposure of organic material, loss of biodiversity and changes in the topography of the landscape due to processes such as subsidence.
Peatlands and fire
In Indonesia, peatlands began to accumulate following the last glacial period as a result of the extremely wet climate conditions. One can find between 160 and 270.000 km2 of peatlands of which the biggest part is located on the sub-coastal lowlands. Not only are they home to numerous species, but they serve as a natural carbon sink, are used for agriculture and settlements, act as a control system, and stabilize the landscape against erosion. In recent decades, the occurrence of extensive degradation, due to human activities, in Indonesia has risen, resulting in the nation becoming the fourth-largest contributor to carbon dioxide emissions.
Peatlands are vital ecosystems of wetlands on land, where water logging conditions inhibit the complete decomposition of plant material. The organic matter accumulates as peat, which can store a large amount of carbon. Peatlands are known to play a crucial role in the mitigation of climate change due to their sequestration abilities of carbon from the atmosphere. But in the last 20 years (2001–2021), there has been an increase in fires which led to a decrease of 18% of the tree cover in Indonesia, producing 19.7 Gt of CO2 emissions. Over 90% of this tree cover loss is due to deforestation. Burning peatlands is a major cause of carbon emissions, releasing carbon dioxide and other greenhouse gases which contribute to climate change. These peat fires are responsible for up to 5% of the world's total annual emissions, as well as significant air pollution that can have serious health implications on local communities. As such, it is essential that effective strategies are put in place to prevent and manage peatland burning both now and in the future.
Biodiversity Indonesia is home to a wide variety of flora and fauna. The main factors affecting the loss of biodiversity in Indonesia are habitat degradation, fragmentation, introduced species, overexploitation, climate change, fires and the economic and political crisis.
Indonesia is home to about 12% of the world's mammals (515 species), ranking it second for fauna diversity after Brazil. The cumulative effect of climate change and anthropological activities have contributed to the decline of animal populations and biodiversity in Indonesia. It has been estimated that 25% of Indonesia's native mammals are endangered. The population of Sumatran elephants has been estimated to have dropped by 35% since the 1990s. Tigers and Sumatran primates population levels have not been maintained in protected areas. The Sumatran tigers and orangutans are also critically endangered animals in Indonesia, despite efforts to increase forest density in nature parks.
In Indonesia, it has been estimated 80% of disasters due to climate change from 1998 to 2018 were flooding (18%), wind storm (26%), landslides (22%) and drought (8%). Increased frequency of such extreme weather events can have direct and indirect impact on species richness through habitat destruction, fragmentation, habitat loss and altering ecosystem processes. Indonesia has about 10% of the world's flowering plant species, 16% of the world's reptiles and 17% of the total species of birds. Despite Indonesia ranking highly on species richness and species diversity, logging, deforestation, agricultural practices and disasters are placing species under constant threat.