Nearly 1,500 scientists are calling on Congress to uphold the scientific foundations of the Endangered Species Act – an environmental law which has faced numerous attacks from GOP lawmakers who consider the policy federal overreach.

"Decisions relating to listings and management of species should be free from political interference," the letter, which was signed by 1,452 scientists,argues.

"Alarmingly, government officials have attempted to inappropriately suppress or manipulate the science used in federal endangered species decisions or interfere with scientists' ability to carry out their work. Such interference is unacceptable and must end."

The Endangered Species Act (ESA), which became law in 1973, was set up to create a science-based process for determining which species are at risk and which species need special protections.

Since the law's inception, the evidence-based process has helped save numerous iconic American species, including the national bird symbol of the US, the bald eagle.

In fact, according to the authors of the letter, the law has saved 99 percent of the listed species from going extinct.

"Well-established scientific processes, such as peer-reviewed science, studies conducted in accordance with sound and objective practices, and data collected by accepted methods, ensure that the science used to conserve species is independent, objective, and credible," the letter continues.

The letter comes in the wake of numerous, political attempts by Congress to chip away at the law's science-based decision making.

A GOP bill introduced to the Senate last year, for example, sought to prohibit species that are only found within a single state from being subject to the ESA.

If the measure had not been shut down in court, it would have stripped protections from nearly 1,100 endangered species.

This is by no means the only example. Since the 115th Congress was sworn in last year, lawmakers have introduced at least 75 legislative attacks which would strip federal protections from specific species or undercut the ESA, according to the Center for Biological Diversity.

One of the proposed bills would allow the US Fish and Wildlife Service and NOAA Fisheries to deny that a species is endangered due to the economic impacts of the listing.

Another would remove protections for at-risk non-native species within the US.

Such measures have been proposed despite overwhelming support for the ESA among the American public, with 90 percent of the public strongly supporting or somewhat supporting the law.

Scientists who signed the letter to Congress are worried that the government is substituting "arbitrary political judgments" for "effective science-based decision making."

"Congress should not interfere with the scientific method by legislating or restricting definitions of science, especially when such actions could compromise the ability of scientific experts in government agencies to implement the Endangered Species Act," the letter argues.

The scientists urged Congress to not only uphold the act, but to also ensure that it is sufficiently funded and supported.

"It is of lasting importance for our common good that the scientific principles embodied in the Endangered Species Act be preserved, and that the law be fully funded and implemented," the letter concludes.

"We urge you to strongly oppose any efforts to reform the Endangered Species Act that would chip away at its scientific foundation, which would inevitably undermine the science underlying the law and lead to more species extinctions."

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