Tag: carbon

According To Researchers, Global Carbon Emissions Rising Again After Brief Plateau

For three years in a row, the world’s carbon emissions were virtually stable — holding steady after decades of growth.

But now they’re on the rise again, which is bad news for efforts to fight climate change, according to a team of researchers who have released a new study on the topic.

Seventy-six scientists from around the world contributed to the Global Carbon Project, or GCP, which released its annual “Carbon Budget” yesterday.

The budget estimates that total global carbon emissions from fossil fuels and industrial sources will rise by 2 percent in 2017.

There’s a fair amount of uncertainty in that projection, with possible values from .8 percent to 3 percent — but the researchers are confident it represents an overall rise, fueled in part by changes in the Chinese economy.

The anticipated change is a “big rise,” lead author Corinne Le Quéré tells NPR. “And this is contrary to what is needed in order to tackle climate change.

It’s a shift from the more hopeful findings from the last few years. From 2014 to 2016, according to the GCP analysis, the rate of emissions was basically flat.

Scientists agree that a reduction in carbon emissions is necessary to keep the global warming at 2 degrees Celsius or less, the target established by the global accord on climate change.

That level of climate change is still projected to have a range of damaging effects, including devastation for some island nations — but it will be far from the worse-case scenario projected if emissions continue to rise.

The increase in carbon emissions is not distributed evenly around the world.

The U.S. and the countries of the European Union, which once generated nearly all of the world’s fossil-fuel and industrial carbon emissions, now contribute less than half of the world’s cumulative emissions.

Their contributions are expected to continue to fall in 2017, albeit at a lower rate than they had previously been falling.

Annual Global Fossil Fuel And Cement Emissions
Total global emissions from fossil fuels and cement production (which the Global Climate Project analyzes to quantify industrial carbon output) have been rising, in general, for decades. The pace had slowed to a near standstill over the last three years. This year, however, researchers anticipate a 2 percent rise in the annual release of carbon dioxide from fossil fuels and industry.

Emissions from China, India and the rest of the world, however, are projected to show marked increase in 2017.

The result is “an emissions tug-of-war,” as the CICERO Center for International Climate Research put it in a press release.

That makes it hard to tell what’s going to happen next, because the trend is “so fragile,” as Le Quéré told NPR yesterday.

It’s the difference between emissions rising in parts of the world and decreasing in other parts of the world,” she says. Overall? “Frankly, it could really go either way.

And it’s crucial for that upward trend to start moving down, and quickly, she says.

She points to already-evident consequences of global warming: warmer oceans that can fuel more powerful storms and rising sea levels that cause more devastating coastal surge damage.

In order to tackle climate change emissions you have to go down to almost zero” emissions, she says. “The faster we do it, the more we limit the risks from climate change.

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Pass it on: Popular Science

Carbon Nanotube Yarn Generates Electricity When Stretched

Wearable makers have long sought to harvest electricity from your movement, but current tech is expensive and inefficient.

However, researchers from Texas and South Korea have discovered a promising method using our good old friend, the carbon nanotube.

The team twisted the lightweight tubes into tight, elastic-like coils, so that they rotate and generate electricity when stretched.

The threads (called “twistron”) could lead to new types of generators or self-powered wearables that can track your heart rate and breathing.

As shown below, the nanotube threads must be spun very tightly to have the right amount of elasticity.

When pulled, the change in volume and friction frees electrons from the threads, which can be released when dunked in an electrolyte like salt water.

When you insert the carbon nanotube yarn into an electrolyte bath, the yarns are charged by the electrolyte itself,” says research lead Dr. Na Li. “No external battery, or voltage, is needed.”

The energy generated from a single thread is enough to power an LED, and when lumped together, they can put out 250 watts per kilogram when stretched at 30 times per second.

No other reported harvester provides such high electrical power or energy output per cycle as ours for stretching rates between a few cycles per second and 600 cycles per second,” said Li.

In the lab, the team sewed twistron harvesters into a shirt, with the electrolyte integrated via o a gel also woven into the fabric.

When subjects breathed normally, it generated an electrical signal that could power a wearable tracker, for instance.

The team also sought to find out if ocean waves could both stretch the nanotubes and act as an electrolyte.

They waded into the South Korean surf and placed a 4-inch piece of the yarn weighing about the same as a mosquito between a float and a sinker.

That stretched the yarn about 25 percent and generated a small amount of current.

As with all things nanotube, however, cost is an issue. “If our twistron harvesters could be made less expensively, they might ultimately be able to harvest the enormous amount of energy available from ocean waves,” said co-author Dr. Ray Baughman.

He adds, though that they’re perfect for wearables. “Just 31 milligrams of carbon nanotube yarn harvester could provide the electrical energy needed to transmit a 2-kilobyte packet of data over a 100-meter radius every 10 seconds.

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Pass it on: Popular Science