Thursday, December 16, 2021

Microbes in oceans and soils are evolving to eat PLASTIC

Researchers in Sweden measured samples of DNA at hundreds of locations around the world, taken from both soil and water.

They found 30,000 enzymes in these DNA samples that have the potential to degrade 10 different types of commonly used plastic, including the widely-used polyethylene terephthalate (PET).

What's more, there appears to be a higher concentration of plastic-eating microbes where there is more plastic waste for them to break down.

It's thought the soaring use of plastic for packaging over the last 70 years has given 'sufficient evolutionary time' for various microbes present in the environment to respond to these compounds.

PET, short for polyethylene terephthalate, is the most common thermoplastic polymer in the world.

PET is a clear, strong, and lightweight plastic that is widely used for packaging foods and beverages, especially convenience-sized soft drinks, juices and water.

Virtually all single-serving and 2-litre bottles of carbonated soft drinks and water sold in the US are made from PET.

Global warming caused by CO2 emissions, and environmental pollution caused by waste PET disposal, are considered as two urgent environmental issues.

Mass-production of plastic has exploded from around 2 million tonnes per year in 1950 to around 380 million, according to Our World in Data.

Some of the locations that contained the highest amounts were notoriously highly polluted areas, including the Mediterranean Sea and South Pacific Ocean.

The new study was led by researchers at the Chalmers University of Technology (CUT), and published in the journal mBIO.

'Using our models, we found multiple lines of evidence supporting the fact that the global microbiome's plastic-degrading potential correlates strongly with measurements of environmental plastic pollution,' said author Aleksej Zelezniak.

This is 'a significant demonstration' of how the environment is 'responding to the pressures we are placing on it', he said.

Using synthetic biology – redesigning organisms for useful purposes – is of crucial importance in the battle against waste, as natural plastic degradation processes are very slow, the researchers say.

For instance, the predicted lifetime of a polyethylene terephthalate (PET) bottle under ambient conditions ranges from 16 to 48 years.

The US produced 42 million tonnes of plastic waste in 2016, making it 'by far' the biggest contributor to plastic waste, a recent report reveals.

About 1 million tonnes [2%] of this total ended up in the world's oceans, according to the report from the National Academy of Sciences.

At 42 million tonnes, the US contribution to the world's plastic waste is over twice as much as China, and more than the 28 countries of the EU (including the UK) combined.

The US should create a national strategy by the end of 2022 to reduce its contribution to plastic waste, National Academies of Sciences says.

It's already known that different enzymes have the ability to degrade different plastics. In 2016, researchers in Japan discovered a bacterium that was feeding on the widely-used PET.

The bacterium, called Ideonella sakaiensis 201-F6, is able to use PET as its source of energy, they reported.

The Japanese team's further investigation identified enzymes that work with water to break down PET into its simpler monomer building blocks.

For the new study, the researchers took soil and water samples from 169 locations in 38 countries, including the US, India, China, Australia, and the Atlantic and Pacific oceans.

Among the samples, researchers used computer modelling to search for microbial enzymes with plastic-degrading potential.

This information was then cross-referenced with the official numbers for plastic waste pollution across countries and oceans.

The researchers controlled for any 'false positives' using data from the human microbiome – the collective genomes of microorganisms in our gut, which is not thought to contain plastic-eating enzymes.

In total, over 30,000 enzyme 'homologues' were found with the potential to degrade 10 different types of commonly used plastic.

Homologues are members of protein sequences sharing similar properties.

'This is a surprising discovery that really illustrates the scale of the issue,' said author Jan Zrimec at the National Institute of Biology in Slovenia.

'Currently, very little is known about these plastic-degrading enzymes, and we did not expect to find such a large number of them across so many different microbes and environmental habitats.'

The researchers believe that their results could potentially be used to discover and adapt enzymes for novel recycling processes.

'The next step would be to test the most promising enzyme candidates in the lab to closely investigate their properties and the rate of plastic degradation they can achieve,' said Zelezniak.

'From there you could engineer microbial communities with targeted degrading functions for specific polymer types.'


How Carbon Dioxide Regs Could Actually Hurt Renewables

GE is telling the White House that if the Environmental Protection Agency sets too stringent greenhouse gas regulations for existing power plants, it could have the unintended consequence of limiting the amount of renewable energy the grid can handle.

The EPA is proposing rules for power plants that would limit their carbon dioxide emissions. The rules would make life hard for coal plants, but are supposed to allow natural gas power plants to keep running—since they emit much less carbon dioxide.

But the rules could actually shut down (or limit the operation of) a certain kind of natural gas power plant—a type of plant that’s essential for incorporating renewable energy into the power grid. These are natural gas plants designed to quickly change power output to accommodate fluctuations in electricity production from wind farms and solar power plants. When they ramp up and down, they operate less efficiently, so they emit more carbon dioxide.The plants might not be able to ramp up and down fast enough to accommodate renewables, while still meeting stringent regulations.

GE argues that by making it harder to use renewable energy, a rule that shut down these natural gas power plants could actually lead to increased total carbon dioxide emissions.

The problem highlights how hard it will be to get off fossil fuels. We’re going to need major innovations in energy storage technologiesto allow utilities to compensate for renewable energy intermittency without relying on natural gas plants. Right now, batteries are too expensive to replace natural gas power (see “Cheap Batteries for Backup Renewable Energy”).

We’ll also need large amounts of low-carbon electricity that isn’t intermittent, such as geothermal power, nuclear power, and fossil fuel power where the carbon dioxide emissions are captured and stored (see “Safer Nuclear Power, at Half the Price”).


Solar pandas are nice but coal is power

“The Chinese government can put in these fabulous looking solar panels on the sides of mountains that are in the shape of pandas and it’s all very very attractive, but the reality is, they need fossil fuels.” ~ Patricia Adams

China climate expert, and author of China Goes Green: Coercive Environmentalism for a Troubled Planet, Judith Shapiro believes the Chinese Communist Party is serious about climate change and views it as a national security risk and a possible new threat to its hold on power.

Shapiro points out the CCP is “well aware” that sea levels are rising on its coastlines, glaciers are melting on the Tibetan Plateau and extreme weather events across the country have become increasingly common. Why wouldn’t they be serious about curbing C02 emissions?

The future of the CCP is tied to C02 emissions says Patricia Adams, China monitor for five decades and author of The Red and the Green: China’s Useful Idiots. Emissions, says Adams, are indicators that factories are running, car purchases are high and standards of living are improving.

Get off coal? Coal is needed for conversion to gas or liquid form as a means to reduce China’s urban smog, says Adams. That conversion produces twice as much C02 but citizens, she says, don’t care about that. They care about “the real killer pollutants” and it’s those killers the CCP has to curb to ensure its legitimacy.

Other countries can pursue net-zero targets and undermine their economies, says Adams. The CCP won’t be doing that.


Australia: Chairman of major bank says the bank won’t pull the plug on fossil fuel projects anytime soon

At the bank’s annual general meeting on Wednesday, Westpac chairman John McFarlane ruled out pulling the plug on fossil fuels projects, which he said will continue to be around for “some time”, despite saying it would become easier to cut them off.

“But given this is Australia, it’s not the right answer. This country does need us to finance various sectors, including electricity generation,” he said.

“We know gas will be with us for some time for base load [power]. We’re not going to be able to deal with renewables immediately.”

In a set of prepared remarks, McFarlane defended the bank’s performance on climate change, reminding shareholders that the bank has “the greatest exposure to greenfield renewables and the least to fossil fuel extraction” of the four major banks.

But that didn’t stop shareholders peppering the chairman with demands for a wind-down on fossil fuels lending, which they said flies in the face of the bank’s commitment to support net-zero emissions by 2050.

As it stands, Westpac has committed to winding down all fossil fuel financing by 2030, but has yet to outline a plan for getting there. Until then, McFarlane said, the bank is trying to straddle a “middle ground”.

“In all honesty, we are doing a reasonable job, and we are doing a better job than some of our competitors,” he said.

McFarlane said formal criteria for reducing fossil fuel funding, which could include a new set of targets, will not come until at least 2023.

“Further research is underway to develop Paris-aligned sector financing strategies and portfolio targets for six of our most climate-exposed sectors representing most of our emissions,” he said.

“Our analysis will consider the latest developments from the International Energy Agency and the IPCC.”

Analysts over at the environmental banking lobby group Market Forces, however, said the bank is having it both ways.

The group, which was responsible for one of two resolutions calling for better disclosure of fossil fuel lending, said Westpac has failed to square up its policies and practices, with its commitments to the Paris Agreement, and net-zero emissions by 2050.

Early last year, Westpac opened its chequebook to Whitehaven Coal, which secured $110 million from the bank. Come November, went back to the sector, this time to the major oil and gas company, Santos, which was able to secure $US25 million in funding.

Shareholders questioned McFarlane on the issue, which has been made worse by the fact that the Commonwealth Bank of Australia and ANZ have each wound down funding for new coal and gas projects like Whitehaven.

But that doesn’t mean they’re beyond reproach on the issue. Both ANZ and NAB are expected to face similar questions when their annual general meetings take place on Friday.




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