The globe is heating up, but not to the surprise of many. We humans have engineered this reality by continuously adding heat-trapping greenhouse gases (notably carbon dioxide, methane, nitrous oxide and synthetic fluorinated gases) to the atmosphere. Aftermaths are alarming, virtually sabotaging the rhythms of climate that all living things rely upon. The unpredictable climate scenario has challenged all life forms.
We might argue that natural factors such as volcanic eruptions and variations in solar radiations are also contributing factors, but these are fairly short cycles of unpredictability that accounts for about two percent of global warming scenario. Anyways, looking ahead we are held in a confused state of mind of how to cope up with the changes. We are yet to figure out the fate of the coasts, forests, farms, mountains and most importantly, the intimidated biodiversity that is sustained in these sensitive ecosystems.
Biodiversity loss due to global warming has been linked to a loss of local species, a rise in illnesses, and mass mortality of plants and animals. On land, higher temperatures have compelled many animals and plants to migrate poleward latitudes or higher heights, with far-reaching effects on ecosystems. Every degree of global warming has increased the likelihood of species extinction.For instance, a report by the Intergovernmental Panel on Climate Change (IPCC)- The United Nations body for assessing science related to climate change- has projected that about 18% of insects, 16% of plants, and 8% of vertebrate species will lose half of their wild habitats, driving them to extinction, if we reach the 2 oC threshold. Hence, all the nations should be a party to “nature friendly” investment development programmes, safeguarding biodiversity loss at each stage of development.
Endemic species that are found restricted to one geographical region will be facing the most obstacles than the native or introduced species if warming exceeds 3 oC due to their isolated habitats and very limited space. Having said that, we are aware of the fact that mitigating the climate change portfolio might not be a foolproof approach for the rescue of endemic species, since threats come in many other forms such as land-use change, overexploitation, and urbanisation. For the endemic species it is largely the case of mismatch between genetic adaptations and the prevailing environmental conditions (maladaptation). Another impact include hybridization- interbreeding as species’ habitats change- leading to genomic erosion and susceptibility to extinction. Endemic invertebrate fauna shows high diversity and is more vulnerable to extinction.For instance, molluscs (the soft-bodied organisms such as snails, slugs, clams, etc.) has the highest rate of extinction and insects have seen 6% of the total animal extinction (IUCN Red List 2020).
According to the Food and Agriculture Organizations of the United States (FAO) 2020, 40% of insects serving as pollinators are facing extinction on a global scale. This is unprecedented, but it has to be said that invertebrate biomass is under-represented in most Red List compendiums including the IUCN Red List. On the contrary, the Korean Red List of Endangered species (2014) has made a sincere effort to quantify the invertebrate faunal diversity and the proportion of endemic species. The species vulnerable to extinction (especially molluscs and some taxa belonging to insects among invertebrates) due to climate change and other human-based interventions have been Red Listed and given priority under conservation policies.The Indian side needs to work on a disaster preparedness scale as only a tiny fraction of the threatened invertebrate species has been included in the Wildlife Protection Act (1972). Initiatives for the documentation of invertebrates in the biodiversity-rich zones should be strengthened by intersecting it with the environmental data.
More essential would be to promote the development of national and thematic biodiversity observation networks to foster biodiversity monitoring across a range of essential biodiversity variables. Biotechnological approaches such as the reference genome and transcriptome approaches are given unprecedented coverage for understanding local adaptation and genetic rescue of the invertebrate fauna that are facing extinction due to global climate change. Identification of fitness traits and locally adapted variants can act as informed definitions of conservation units and on this basis can identify source populations for supporting genetic rescue programmes. Hence, an evidence-based decision making could be nurtured to combat invertebrate extinctions and protect the planet from an erosion of ecosystem health that looks ominous in the wake of climate change.
(The writer is Associate Professor, PG Department of Biosciences and Biotechnology, Fakir Mohan University, Baleswar, and National Research Foundation of Korea fellow, Korea Native Animal Resources Utilisation Convergence Research Institute (KNAR) (Ministry of Education), Soonchunhyang University, Korea)