The UN's chief called Tuesday for an end to a "toxic cover-up" by companies as a sweeping report said they cannot claim to be net zero if they invest in new fossil fuels, cause deforestation or offset emissions instead of reducing them.
Antonio Guterres said businesses as well as cities and regions should update their voluntary net zero pledges within a year to comply with the recommendations by UN experts, as he trained his sights on fossil fuel firms and "their financial enablers".
"Using bogus 'net-zero' pledges to cover up massive fossil fuel expansion is reprehensible. It is rank deception," he said at the launch of the report at the COP27 conference in Egypt.
"This toxic cover-up could push our world over the climate cliff. The sham must end."
The UN expert panel, convened by Guterres after UN climate talks in Glasgow last year, set its sights on drawing a "red line" around greenwashing in net zero targets from companies, cities and regions.
A huge surge in decarbonisation pledges in recent months means that around 90 percent of the global economy is now covered by some sort of promise of carbon neutrality, according to Net Zero Tracker.
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"It's very easy to make an announcement that you are going to be net zero by 2050. But you have to walk the talk and what we've seen is that there is not enough action," said Catherine McKenna, Canada's former environment and climate change minister, who led the panel.
"We have to do two things to reach net zero -- we need to drastically reduce emissions, and we need to invest in clean (energy)," she told AFP.
She added it was currently "extremely hard" to properly evaluate whether firms were cutting emissions and called for greater transparency.
The report lists a slew of recommendations, including calling on governments to begin putting in place binding regulations.
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