When a tree-planting advocate receives threats of sexual assault and violence against her children, it is perhaps a red flag that the practice of healthy discussion has gone terribly awry.

In the heat of a carbon pollution tax debate, Australia’s top climate change scientists are facing an attack that has led some to go into hiding.

Over 30 researchers across Australia told The Canberra Times that they are being harassed with abusive emails. The violent threats haven't just targeted the scientists, but their families as well.

Why are people so angry? AFP explains that a debate is raging over Prime Minister Julia Gillard's plans to reduce pollution through a tax on carbon emissions. The goal is to tax polluters with a fixed price levy, and then move to an emissions trading scheme within the next five years. Reuters reports that Australia is the highest emitter per capita due to its reliance on coal (providing 80 percent of the nation’s power.)

The seemingly excessive anger towards scientists was fueled a few weeks ago when a new ad campaign featuring Cate Blanchett launched, advocating for the carbon tax. The ad suggests that big companies should pay for their pollution. The carbon tax proposal would result in more jobs, better health for children, and, as Blanchett says, “finally do something about climate change.” The ad appears to be rather understated (there is literally a singing birds sound cue), and yet the clip further enraged some people. As Grist writes, “Positivity + babies + gorgeous actresses seems like a pretty good recipe for getting people to, if not agree with you, at least not want to KILL YOU.”

The Guardian reports that Tony Abbott, the conservative opposition leader who once described man-made climate change as “crap,” critiqued the advertisement and actor, stating, "People who are worth $53m have a right to be heard – but their voice should not be heard ahead of the ordinary working people of this country.”

One recent poll found that 58 percent of the 500 voters questioned were against the tax. The proposal’s opposition argues that the carbon tax would damage the economy.

Meanwhile, Treasurer Wayne Swan argues "Our economy will continue to grow solidly while making deep cuts in carbon pollution," according to a speech excerpt provided by Reuters. According to Australia's ABC News, the debate comes on the heels of a new report commissioned by the Federal Government, predicting that by the end of the century, thousands of buildings could be destroyed with $226 billion worth of assets at risk due to climate change.

The problem is that this debate has in some cases materialized into serious anger.

According to The Canberra Times, The Australian National University moved high-profile climate scientists into secure buildings after they received explicit threats.

Scientists from other universities have been threatened as well. One scientist told The Canberra Times, ''If you want to find me, it's impossible unless you make an appointment, sign in with some form of photo identification, and are personally escorted to my door… That's directly as a result of threats made against me.''

One researcher told the paper of an instance where her photo appeared in an article promoting a community tree-planting day -- she then received threats of sexual assault and violence against her children. Another scientist received death threats and was advised by police to install a ''panic button'' in his office.

Many have changed their home security systems, deleted social media accounts, and switched to unlisted phone numbers after receiving threats to their homes.

Australia's new chief scientist, former ANU vice-chancellor Professor Ian Chubb, denounced the threats, stating, ''These hurtful attacks are intended to intimidate scientists, to scare them off and stop them from participating in public discussions on climate change. They are the antithesis of democratic debate.”

Christine Milne, Australian Greens deputy leader, said the emails were ''an orchestrated, extremist anti-science campaign attempting to threaten and intimidate people into silence.''

Professor David Koroly from the University of Melbourne tells Australia's ABC News that he receives threats every time the media interview him. Yet, he argues, "It is still very important that climate scientists present the best available information to the community, to the business community and to politicians and that we seek to protect our individual safety, but that we still provide the best available climate science."