The complex network of interdependencies between plants and animals multiplies the species at risk of extinction due to environmental change, according to a JRC study.

In the case of global warming, predictions that fail to take into account this cascading effect might underestimate extinctions by up to 10 times.

As an obvious, direct consequence of climate change, plants and animals living in a given area are driven to extinction when the local environmental conditions become incompatible with their tolerance limits, just like fish in an aquarium with a broken thermostat.

However, there are many elusive drivers of species loss that go beyond the direct effects of environmental change (and human activity) which we still struggle to understand.

In particular, it is becoming clearer that co-extinctions (the disappearance of consumers following the depletion of their resources) could be a major culprit in the ongoing biodiversity crisis.

While the concept of co-extinction is supported by a sound and robust theoretical background, it is often overlooked in empirical research because it's extremely difficult to assess.

New JRC Study on Co-Extinctions

A new study led by the JRC took on this challenge in order to determine the importance of co-extinctions in conditions of environmental change.

JRC scientist Giovanni Strona, in collaboration with Professor Corey Bradshaw from Flinders University in Adelaide, Australia, constructed 2000 "Virtual Earths", which they populated with thousands of plants and animals organized into a global system of inter-connected food-webs.

They then subjected the virtual Earths to extreme trajectories of environmental change, consisting in either a "global warming", i.e. a linear, monotonic increase in temperature, or a "nuclear winter", i.e. a progressive cooling, such as that which could follow multiple nuclear detonations or an asteroid impact.

They then tracked the loss of species diversity within two separate scenarios up to complete life annihilation.

In the first scenario, they only accounted for the extinction of a species when the temperature became too high or too low for that species to tolerate.

In the second scenario, starting from the extinctions triggered by the mismatch between local temperature and species tolerance limits, they also simulated co-extinction cascades.

By comparing the two scenarios, the scientists were able to provide a quantitative estimate of the relative importance of co-extinctions in planetary biodiversity loss.

They found that failing to account for interdependencies between species led to underestimation of the magnitude of mass extinctions triggered by climate change by up to 10 times.

Giovanni reflects that "conservationists and decision makers need to move fast beyond a species-specific approach, and look with increasing attention at species interaction networks as a fundamental conservation target. Whenever a species leaves our planet, we lose much more than a name on a list".

Global Warming: IPCC Special Report on Global Warming of 1.5°C confirms the utmost urgency to act

The study also explored the worst possible scenario of temperature change due to global warming.

According to the simulations, 5-6°C of warming would be enough to wipe out most life on the virtual Earths the scientists created.

Giovanni recognises that "there are obvious limitations in our ambitious model, due to the multiple challenges of building realistic global ecological systems.

On the one hand, our results are consistent with real-world patterns for which we have empirical evidence.

This make us confident that the many assumptions we had to take in order to build a functional model are sound. On the other hand, however, it would be misleading to just focus on raw numbers."

What is clear is that a warming Earth will put increasing pressure on the planet's biodiversity, and co-extinctions will add to that impact.

While it is unlikely that the Earth will become 5-6°C warmer in the near future, it is quite likely that global temperatures will continue to increase.

The debate between the Centre and the Kerala government on the offer and acceptance of foreign aid following the floods has drawn attention away from the core question at stake—one of fiscal federalism. The goods and services tax (GST) has increased the centralization of fiscal powers, limiting the autonomy of states to raise their own revenue for public expenditure. The interplay of the fledgling GST regime with the role and responsibilities of the Centre and states under the Disaster Management Act, 2005, (DMA) has led to an uncharted situation.

Public health, roads, bridges and ferries, inland waterways, agriculture and land are state subjects, under List II of the Constitution. The Kerala government has sought to impose a cess of 10% to finance the rebuilding of the state following the devastation caused by floods. In terms of Article 279A of the Constitution, the GST Council is the forum for approving any new state tax on account of a natural calamity or disaster.

Cesses are traditionally considered bad—“lazy taxes”—in public finance, a fact acknowledged in the Economic Survey 2013-14 (released in July 2014). The survey recommended the eventual removal of all cesses (although several central cesses, including the Swachh Bharat cess continue). During deliberations surrounding the GST Act, Union finance minister Arun Jaitely even resisted introducing an 18% cap on GST in the Constitution on the ground that a natural disaster (he cited the example of a flood) may necessitate additional tax.

Given that the taxation powers (and consequently, budgets) of states are significantly constrained on account of GST, it is incumbent on the Centre to share the states’ burdens in times of crisis. Previously, states received 60% of all indirect taxes, while the Centre received 40%. This has now changed to a 50-50 division, even though the Centre forgoes cesses. The GST is believed to increase state revenue in the long term, but, at the moment, several states, including Kerala, have reported significant reduction in tax revenues under the new tax regime. Kerala has a revenue deficit of ₹12,860 crore, or 1.7% of the state gross domestic product (SGDP). The state government had budgeted its total expenditure to rise 14% to ₹1.3 trillion in 2018-19—before the floods struck.

State governments have increased expenditure responsibilities (on account of the Ujwal Discom Assurance Yojana scheme, pay revisions and farm loan waivers)—more so in times of crises. Without an adequate share of taxes, they are pushed to borrow more, hardly a sustainable source of financing public expenditure. Kerala has requested an enhancement of its borrowing limit. Deputy governor of the Reserve Bank of India, B.P. Kanungo, recently warned against fiscal slippage and rising borrowing by states.

This problem is compounded by the lack of fund outlay under the DMA. While the DMA, which predates the GST Act, expands the role of the Centre in disaster management, this has not resulted in adequate budgetary apportionment for states. The prime minister is the ex-officio chairperson of the National Disaster Management Authority (NDMA), and secretaries of the concerned central government ministries and departments are members of the National Executive Committee (NEC). Similar arrangements are made at the state and district levels. The NEC is responsible for formulating the national plan, which the central government is to finance by making “adequate provisions”.

What constitutes “adequate provisions”, particularly after the implementation of GST? By concentrating taxing power, the 122nd amendment to the Constitution has tilted the balance of federal powers towards the Centre. Accordingly, it is not unreasonable for states to expect that the Centre will extend financial support during disasters.

Despite the statutory role of the Centre under the DMA, it places primary responsibility for disaster management on the states (as noted, for instance, in the NDMA’s 2016-17 annual report). According to a PRS legislative research analysis of the demand for grants by the Union ministry of home affairs (MHA) in 2017-18, roughly 80% of the MHA’s budget expenditure went to the police, while only 6% was spent on disaster management, rehabilitation of refugees and migrants, census and Cabinet expenses, put together. Further, the Union ministry of finance’s notice on demands for grants for transfers to states (2018-19) shows a demand of ₹10,000 crore as budgeted expenditure for 2018-19 for the state disaster response fund (SDRF) and ₹2,500 crore for the national disaster response fund (NDRF), with a clear stipulation that the “first charge” of relief expenditure is on the SDRF.

Moreover, as per the operational guidelines for the NDRF, the fund is intended only to provide immediate relief to disaster victims. Neither the NDRF nor the SDRF can be used for restoration or reconstruction in the aftermath of a disaster. These expenses are to be met from normal budgetary heads or plan funds. In 2016, the Centre decided not to establish a mitigation fund, finding that these expenses could be met through its other schemes.

The GST Council has now been asked to determine whether Kerala can raise revenues through a disaster cess. If the council finds that such a cess will destroy the uniformity of tax rates across the country, the Centre must step in with additional disaster relief to prevent excessive borrowing by the state and the makings of another disaster.

source: https://www.livemint.com/