Ocean carbon uptake widely underestimated

https://phys.org/news/2020-09-ocean-carbon-uptake-widely-underestimated.html

ocean
Credit: CC0 Public Domain

The world’s oceans soak up more carbon than most scientific models suggest, according to new research.

Previous estimates of the movement of carbon (known as “flux”) between the atmosphere and oceans have not accounted for  differences at the water’s surface and a few metres below.

The new study, led by the University of Exeter, includes this—and finds significantly higher net flux of carbon into the oceans.

It calculates CO2 fluxes from 1992 to 2018, finding up to twice as much net flux in certain times and locations, compared to uncorrected models.

“Half of the carbon dioxide we emit doesn’t stay in the atmosphere but is taken up by the oceans and land vegetation ‘sinks’,” said Professor Andrew Watson, of Exeter’s Global Systems Institute.

“Researchers have assembled a  of near-surface carbon dioxide measurements—the “Surface Ocean Carbon Atlas” (http://www.socat.info) – that can be used to calculate the flux of CO2 from the atmosphere into the .

“Previous studies that have done this have, however, ignored small temperature differences between the surface of the ocean and the depth of a few metres where the measurements are made.

“Those differences are important because carbon dioxide solubility depends very strongly on temperature.

“We used  to correct for these temperature differences, and when we do that it makes a big difference—we get a substantially larger flux going into the ocean.

“The difference in ocean uptake we calculate amounts to about 10 per cent of global fossil fuel emissions.”

Dr. Jamie Shutler, of the Centre for Geography and Environmental Science on Exeter’s Penryn Campus in Cornwall, added: “Our revised estimate agrees much better than previously with an independent method of calculating how much carbon dioxide is being taken up by the ocean.

“That method makes use of a global ocean survey by research ships over decades, to calculate how the inventory of carbon in the ocean has increased.

“These two ‘big data’ estimates of the ocean sink for CO2 now agree pretty well, which gives us added confidence in them.”

The paper, published in Nature Communications, is entitled: “Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean  inventory.”

Shockingly Simple: How Farmland Could Absorb an Extra 2 Billion Tonnes of CO2 From the Atmosphere Each Year

Rock Dust Farmland

Credit: Dr Dimitar Epihov

2 Billion Tonnes of CO2 Could be Absorbed From the Atmosphere Each Year by Applying Rock Dust to Farmland

Adding crushed rock dust to farmland could draw down up to two billion tonnes of carbon dioxide (CO2) from the air per year and help meet key global climate targets, according to a major new study led by the University of Sheffield.

  • Major new study shows adding rock dust to farmland could remove carbon dioxide (CO2) equivalent to more than the current total emissions from global aviation and shipping combined — or around half of Europe’s current total emissions
  • Research identifies the nation-by-nation potential for CO2 drawdown, as well as the costs and the engineering challenges involved
  • Findings reveal the world’s highest emitters (China, India and the US) also have the greatest potential to remove CO2 from the atmosphere using this method
  • Scientists suggest unused materials from mining and the construction industry could be used to help soils remove CO2 from the atmosphere

Adding crushed rock dust to farmland could draw down up to two billion tonnes of carbon dioxide (CO2) from the air per year and help meet key global climate targets, according to a major new study led by the University of Sheffield.

The technique, known as enhanced rock weathering, involves spreading finely crushed basalt, a natural volcanic rock, on fields to boost the soil’s ability to extract CO2 from the air.

In the first nation-by-nation assessment, published in Nature, scientists have demonstrated the method’s potential for carbon drawdown by major economies, and identified the costs and engineering challenges of scaling up the approach to help meet ambitious global CO2 removal targets. The research was led by experts at the University of Sheffield’s Leverhulme Centre for Climate Change Mitigation, and the University’s Energy Institute.

Meeting the Paris Agreement’s goal of limiting global heating to below 2C above pre-industrial levels requires drastic cuts in emissions, as well as the active removal of between two and 10 billion tonnes of CO2 from the atmosphere each year to achieve net-zero emissions by 2050. This new research provides a detailed initial assessment of enhanced rock weathering, a large-scale CO2 removal strategy that could make a major contribution to this effort.

The authors’ detailed analysis captures some of the uncertainties in enhanced weathering CO2 drawdown calculations and, at the same time, identifies the additional areas of uncertainty that future work needs to address specifically through large-scale field trials.

The study showed that China, the United States and India – the highest fossil fuel CO2 emitters – have the highest potential for CO2 drawdown using rock dust on croplands. Together, these countries have the potential to remove approximately 1 billion tonnes of CO2 from the atmosphere, at a cost comparable to that of other proposed carbon dioxide removal strategies (US$80-180 per tonne of CO2).

Indonesia and Brazil, whose CO2 emissions are 10-20 times lower than the US and China, were also found to have relatively high CO2 removal potential due to their extensive agricultural lands, and climates accelerating the efficiency of rock weathering.

The scientists suggest that meeting the demand for rock dust to undertake large-scale CO2 drawdown might be achieved by using stockpiles of silicate rock dust left over from the mining industry, and are calling for governments to develop national inventories of these materials.

Calcium-rich silicate by-products of iron and steel manufacturing, as well as waste cement from construction and demolition, could also be processed and used in this way, improving the sustainability of these industries. These materials are usually recycled as low value aggregate, stockpiled at production sites or disposed of in landfills. China and India could supply the rock dust necessary for large-scale CO2 drawdown with their croplands using entirely recycled materials in the coming decades.

The technique would be straightforward to implement for farmers, who already tend to add agricultural lime to their soils. The researchers are calling for policy innovation that could support multiple UN Sustainable Development Goals using this technology. Government incentives to encourage agricultural application of rock dust could improve soil and farm livelihoods, as well as reduce CO2, potentially benefiting the world’s 2.5 billion smallholders and reducing poverty and hunger.

Professor David Beerling, Director of the Leverhulme Centre for Climate Change Mitigation at the University of Sheffield and lead author of the study, said: “Carbon dioxide drawdown strategies that can scale up and are compatible with existing land uses are urgently required to combat climate change, alongside deep and sustained emissions cuts.

“Spreading rock dust on agricultural land is a straightforward, practical CO2 drawdown approach with the potential to boost soil health and food production. Our analyses reveal the big emitting nations – China, the US, India – have the greatest potential to do this, emphasizing their need to step up to the challenge. Large-scale Research Development and Demonstration programs, similar to those being pioneered by our Leverhulme Centre, are needed to evaluate the efficacy of this technology in the field.”

Professor Steven Banwart, a partner in the study and Director of the Global Food and Environment Institute, said: “The practice of spreading crushed rock to improve soil pH is commonplace in many agricultural regions worldwide. The technology and infrastructure already exist to adapt these practices to utilize basalt rock dust. This offers a potentially rapid transition in agricultural practices to help capture CO2 at large scale.”

Professor James Hansen, a partner in the study and Director of the Climate Science, Awareness and Solutions Program at Columbia University’s Earth Institute, said: “We have passed the safe level of greenhouse gases. Cutting fossil fuel emissions is crucial, but we must also extract atmospheric CO2 with safe, secure and scalable carbon dioxide removal strategies to bend the global CO2 curve and limit future climate change. The advantage of CO2 removal with crushed silicate rocks is that it could restore deteriorating top-soils, which underpin food security for billions of people, thereby incentivizing deployment.”

Professor Nick Pidgeon, a partner in the study and Director of the Understanding Risk Group at Cardiff University, said: “Greenhouse gas removal may well become necessary as we approach 2050, but we should not forget that it also raises profound ethical questions regarding our relationship with the natural environment. Its development should therefore be accompanied by the widest possible public debate as to potential risks and benefits.”

Reference: “Potential for large-scale CO2 removal via enhanced rock weathering with croplands” by David J. Beerling, Euripides P. Kantzas, Mark R. Lomas, Peter Wade, Rafael M. Eufrasio, Phil Renforth, Binoy Sarkar, M. Grace Andrews, Rachael H. James, Christopher R. Pearce, Jean-Francois Mercure, Hector Pollitt, Philip B. Holden, Neil R. Edwards, Madhu Khanna, Lenny Koh, Shaun Quegan, Nick F. Pidgeon, Ivan A. Janssens, James Hansen and Steven A. Banwart, 8 July 2020, Nature.
DOI: 10.1038/s41586-020-2448-9

Carbon Dioxide Emissions Near Level Not Seen in 15 Million Years, New Study Warns

Authors of a new study warned Thursday that increasing carbon dioxide in the atmosphere is nearing a level not seen in 15 million years. Dawn Ellner / Flickr / CC by 2.0

By Jessica Corbett

As a United Nations agency released new climate projections showing that the world is on track in the next five years to hit or surpass a key limit of the Paris agreement, authors of a new study warned Thursday that increasing carbon dioxide in the atmosphere is nearing a level not seen in 15 million years.

For the study, published in the journal Scientific Reports, researchers at the University of Southampton in the United Kingdom examined CO2 levels during the Late Pliocene about three million years ago “to search for modern and near future-like climate states,” co-author Thomas Chalk explained in a series of tweets.

“A striking result we’ve found is that the warmest part of the Pliocene had between 380 and 420 parts per million CO2 in the atmosphere,” Chalk told the Guardian. “This is similar to today’s value of around 415 parts per million, showing that we are already at levels that in the past were associated with temperature and sea-level significantly higher than today.”

When CO2 levels peaked during the Pliocene, temperatures were 3ºC to 4ºC hotter and seas were 65 feet higher, the newspaper reported. Chalk said that “currently, our CO2 levels are rising at about 2.5 ppm per year, meaning that by 2025 we will have exceeded anything seen in the last 3.3 million years.”

“We are burning through the Pliocene and heading towards a Miocene-like future,” warned co-author Gavin Foster, referencing a period from about 23 to 5.3 million years ago. It was during the Miocene, around 15 million years ago, when “our ancestors are thought to have diverged from orangutans and become recognizably hominoid,” the Guardian noted.

Reporting on the study elicited concern and calls for action from environmentalists and advocacy groups.

“Every kilo of CO2 we emit is one we have to sequester later, provided the food doesn’t run out first,” tweeted Extinction Rebellion Finland, urging the international community to #ActNow.

Nathaniel Stinnett, executive director of the U.S.-based Environmental Voter Project, also responded to the report on Twitter, saying, “Big Oil and Gas are killing us.”

A new report released Thursday by the U.N.’s World Meteorological Organization (WMO) about global temperatures likely coming in the next five years provoked similar alarm and demands.

“It’s still not too late to avoid the worst effects of the #ClimateEmergency. But governments need to act NOW,” declared Greenpeace, pushing for a #GreenRecovery from the Covid-19 pandemic.

The WMO report projects that the annual global temperature is likely to be at least 1°C warmer than pre-industrial levels in each of the next five years. Although it is “extremely unlikely” the average temperature for 2020–2024 will be 1.5°C warmer than pre-industrial levels, WMO warned certain periods could hit that temperature.

Specifically, there is about a 70% chance that one or more months during those five years will be at least 1.5°C hotter than pre-industrial levels and about a 20% chance that one of the next five years will be at least that warm, according to WMO’s Global Annual to Decadal Climate Update, led by the United Kingdom’s Met Office.

In a statement Thursday, WMO Secretary-General Petteri Taalas also pointed to the coronavirus pandemic—which prompted global lockdowns that briefly caused planet-heating emissions to drop—as an opportunity to pursue bold recovery plans that incorporate policies that combat the climate crisis, such as rapidly transitioning to renewable energy worldwide.

“WMO has repeatedly stressed that the industrial and economic slowdown from Covid-19 is not a substitute for sustained and coordinated climate action,” Taalas said. “Due to the very long lifetime of CO2 in the atmosphere, the impact of the drop in emissions this year is not expected to lead to a reduction of CO2 atmospheric concentrations which are driving global temperature increases.”

“Whilst Covid-19 has caused a severe international health and economic crisis, failure to tackle climate change may threaten human well-being, ecosystems, and economies for centuries,” he continued. “Governments should use the opportunity to embrace climate action as part of recovery program and ensure that we grow back better.”

Taalas added that “this study shows—with a high level of scientific skill—the enormous challenge ahead in meeting the Paris agreement on climate change target of keeping a global temperature rise this century well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5°C.”

While some scientists and activists have criticized the 2015 Paris climate agreement as not ambitious enough, it is backed by nearly all nations on Earth. U.S. President Donald Trump began the one-year withdrawal process in November 2019 but former Vice President Joe Biden, the presumed Democratic presidential nominee, has vowed to rejoin the accord if he wins this year’s election.

Reposted with permission from Common Dreams.

A ‘regime shift’ is happening in the Arctic Ocean, scientists say

https://phys.org/news/2020-07-regime-shift-arctic-ocean-scientists.html?fbclid=IwAR2rlEH5OPhX3qrC5aFzC2ceSLXZYmEd9Gis5QOp4Y-sBnf4iopgmwjvWEk

Arctic Ocean
Credit: Pixabay/CC0 Public Domain

Scientists at Stanford University have discovered a surprising shift in the Arctic Ocean. Exploding blooms of phytoplankton, the tiny algae at the base of a food web topped by whales and polar bears, have drastically altered the Arctic’s ability to transform atmospheric carbon into living matter. Over the past decade, the surge has replaced sea ice loss as the biggest driver of changes in uptake of carbon dioxide by phytoplankton.

The study centers on net primary production (NPP), a measure of how quickly plants and algae convert sunlight and carbon dioxide into sugars that other creatures can eat. “The rates are really important in terms of how much food there is for the rest of the ecosystem,” Arrigo said. “It’s also important because this is one of the main ways that CO2 is pulled out of the atmosphere and into the .”

A thickening soup

Arrigo and colleagues found that NPP in the Arctic increased 57 percent between 1998 and 2018. That’s an unprecedented jump in productivity for an entire ocean basin. More surprising is the discovery that while NPP increases were initially linked to retreating sea ice, productivity continued to climb even after melting slowed down around 2009. “The increase in NPP over the past decade is due almost exclusively to a recent increase in phytoplankton biomass,” Arrigo said.

Put another way, these microscopic algae were once metabolizing more carbon across the Arctic simply because they were gaining more  over longer growing seasons, thanks to climate-driven changes in ice cover. Now, they are growing more concentrated, like a thickening algae soup.

“In a given volume of water, more phytoplankton were able to grow each year,” said lead study author Kate Lewis, who worked on the research as a Ph.D. student in Stanford’s Department of Earth System Science. “This is the first time this has been reported in the Arctic Ocean.”

New food supplies

Phytoplankton require light and nutrients to grow. But the availability and intermingling of these ingredients throughout the water column depend on complex factors. As a result, although Arctic researchers have observed phytoplankton blooms going into overdrive in recent decades, they have debated how long the boom might last and how high it may climb.

By assembling a massive new collection of ocean color measurements for the Arctic Ocean and building new algorithms to estimate phytoplankton concentrations from them, the Stanford team uncovered evidence that continued increases in production may no longer be as limited by scarce nutrients as once suspected. “It’s still early days, but it looks like now there is a shift to greater nutrient supply,” said Arrigo, the Donald and Donald M. Steel Professor in Earth Sciences.

The researchers hypothesize that a new influx of nutrients is flowing in from other oceans and sweeping up from the Arctic’s depths. “We knew the Arctic had increased production in the last few years, but it seemed possible the system was just recycling the same store of nutrients,” Lewis said. “Our study shows that’s not the case. Phytoplankton are absorbing more carbon year after year as new nutrients come into this ocean. That was unexpected, and it has big ecological impacts.”

Decoding the Arctic

The researchers were able to extract these insights from measures of the green plant pigment chlorophyll taken by satellite sensors and research cruises. But because of the unusual interplay of light, color and life in the Arctic, the work required . “The Arctic Ocean is the most difficult place in the world to do satellite remote sensing,” Arrigo explained. “Algorithms that work everywhere else in the world—that look at the color of the ocean to judge how much phytoplankton are there—do not work in the Arctic at all.”

The difficulty stems in part from a huge volume of incoming tea-colored river water, which carries dissolved organic matter that remote sensors mistake for chlorophyll. Additional complexity comes from the unusual ways in which  have adapted to the Arctic’s extremely low light. “When you use global satellite remote sensing algorithms in the Arctic Ocean, you end up with serious errors in your estimates,” said Lewis.

Yet these remote-sensing data are essential for understanding long-term trends across an ocean basin in one of the world’s most extreme environments, where a single direct measurement of NPP may require 24 hours of round-the-clock work by a team of scientists aboard an icebreaker, Lewis said. She painstakingly curated sets of ocean color and NPP measurements, then used the compiled database to build algorithms tuned to the Arctic’s unique conditions. Both the database and the algorithms are now available for public use.

The work helps to illuminate how climate change will shape the Arctic Ocean’s future productivity, food supply and capacity to absorb carbon. “There’s going to be winners and losers,” Arrigo said. “A more productive Arctic means more food for lots of animals. But many animals that have adapted to live in a polar environment are finding life more difficult as the ice retreats.”

Phytoplankton growth may also peak out of sync with the rest of the food web because ice is melting earlier in the year. Add to that the likelihood of more shipping traffic as Arctic waters open up, and the fact that the Arctic is simply too small to take much of a bite out of the world’s greenhouse gas emissions. “It’s taking in a lot more carbon than it used to take in,” Arrigo said, “but it’s not something we’re going to be able to rely on to help us out of our climate problem.”

Australian researchers set record for carbon dioxide capture

carbon dioxide
Credit: CC0 Public Domain

Researchers from Monash University and the CSIRO have set a record for carbon dioxide capture and storage (CCS) using technology that resembles a sponge filled with tiny magnets.

Using a Metal Organic Frameworks (MOFs) nanocomposite that can be regenerated with remarkable speed and low  cost, researchers have developed sponge-like technology that can capture  dioxide from a number of sources, even directly from air.

The magnetic sponge is used to remove carbon dioxide using the same techniques as induction cooktops using one-third of the energy than any other reported method.

Associate Professor Matthew Hill (CSIRO and Department of Chemical Engineering, Monash University) and Dr. Muhammad Munir Sadiq (Department of Chemical Engineering, Monash University) led this research.

In the study, published in Cell Reports Physical Science, researchers designed a unique adsorbent material called M-74 CPT@PTMSP that delivered a record low energy cost of just 1.29 MJ kg-1CO2 , 45 per cent below commercially deployed materials, and the best CCS efficiency recorded.

MOFs are a class of compounds consisting of metal ions that form a crystalline material with the largest surface area of any material known. In fact, MOFs are so porous that they can fit the entire surface of a football field in a teaspoon.

This technology makes it possible to store, separate, release or protect valuable commodities, enabling companies to develop high value products.

“Global concerns on the rising level of greenhouse gas emissions and the associated  has led to renewed calls for emissions reduction and the development of green and renewable alternative energy sources,” Associate Professor Hill said.

“However, existing commercial carbon capture technologies use amines like monoethanolamine, which is highly corrosive, energy intensive and captures a limited amount of carbon from the atmosphere.

“Our research shows the lowest reported regeneration energy calculated for any solid porous adsorbent, including monoethanolamine, piperazine and other amines. This makes it a cheap method that can be paired with renewable solar energy to capture excess  from the atmosphere.

“Essentially, we can capture CO2 from anywhere. Our current focus is for capture directly from the air in what are known as negative emissions technologies.”

For MOFs to be used in CCS applications, it is essential to have materials that can be easily fabricated with good stability and performance.

The stability of M-74 CPT@PTMSP was evaluated by estimating the amount of CO2 and H2O captured and released via the researchers’ magnetic induction swing adsorption (MISA) process over 20 consecutive cycles.

The regeneration energy calculated for M-74 CPT@PTMSP is the lowest reported for any solid porous adsorbent. At magnetic fields of 14 and 15 mT, the regeneration energy calculated for M-74 CPT was 1.29 and 1.44 MJ kg CO2-1.


Explore further

New material captures carbon dioxide

What Causes Climate Change?

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Graph providing evidence that atmospheric CO2 has increased since the Industrial Revolution

  

 

    

Who emits the most CO2?

 

     

   

      

    

  

Seabed fossils show the ocean is undergoing a change not seen for 10,000 years

ocean circulation may have caused a shift in Atlantic Ocean ecosystems not seen for the past 10,000 years, new analysis of deep-sea fossils has revealed.

This is the striking finding of a new study led by a research group I am part of at UCL, funded by the ATLAS project and published in the journal Geophysical Research Letters. The shift has likely already led to political tensions as fish migrate to colder waters.

The climate has been quite stable over the 12,000 years or so since the end of the last Ice Age, a period known as the Holocene. It is thought that this stability is what allowed human civilisation to really get going.

In the ocean, the major currents are also thought to have been relatively stable during the Holocene. These currents have natural cycles, which affect where marine organisms can be found, including plankton, fish, seabirds and whales.

Yet climate change in the ocean is becoming apparent. Tropical coral reefs are bleaching, the oceans becoming more acidic as they absorb carbon from the atmosphere, and species like herring or mackerel are moving towards the poles. But there still seems to be a prevailing view that not much has happened in the ocean so far – in our minds the really big impacts are confined to the future.

Looking into the past

To challenge this point of view, we had to look for places where seabed fossils not only covered the industrial era in detail, but also stretched back many thousands of years. And we found the right patch of seabed just south of Iceland, where a major deep sea current causes sediment to pile up in huge quantities.

Scientists gathered fossils from an area with lots of seabed sediment. Peter SpoonerAuthor provided

To get our fossil samples we took cores of the sediment, which involves sending long plastic tubes to the bottom of the ocean and pushing them into the mud. When pulled out again, we were left with a tube full of sediment that can be washed and sieved to find fossils. The deepest sediment contains the oldest fossils, while the surface sediment contains fossils that were deposited within the past few years.

One of the simplest ways of working out what the ocean was like in the past is to count the different species of tiny fossil plankton that can be found in such sediments. Different species like to live in different conditions. We looked at a type called foraminifera, which have shells of calcium carbonate. Identifying them is easy to do using a microscope and small paintbrush, which we use when handling the fossils so they don’t get crushed.

Electron microscope image of the tiny fossil plankton G. bulloides, a type of foraminifera found during the study. Alessio Fabbrini, UCLAuthor provided

recent global study showed that modern foraminifera distributions are different to the start of the industrial era. Climate change is clearly already having an impact.

Similarly, the view that modern ocean currents are like those of the past couple of thousand years was challenged by our work in 2018, which showed that the overturning “conveyor belt” circulation was at its weakest for 1,500 years. Our new work builds on this picture and suggests that modern North Atlantic surface circulation is different to anything seen in the past 10,000 years – almost the whole Holocene.

The effects of the unusual circulation can be found across the North Atlantic. Just south of Iceland, a reduction in the numbers of cold-water plankton species and an increase in the numbers of warm-water species shows that warm waters have replaced cold, nutrient-rich waters. We believe that these changes have also led to a northward movement of key fish species such as mackerel, which is already causing political headaches as different nations vie for fishing rights.

Members of the team collect ocean sediment. Ian Hall, Cardiff UniversityAuthor provided

Further north, other fossil evidence shows that more warm water has been reaching the Arctic from the Atlantic, likely contributing to melting sea ice. Further west, a slowdown in the Atlantic conveyor circulation means that waters are not warming as much as we would expect, while furthest west close to the US and Canada the warm gulf stream seems to be shifting northwards which will have profound consequences for important fisheries.

One of the ways that these circulation systems can be affected is when the North Atlantic gets less salty. Climate change can cause this to happen by increasing rainfall, increasing ice melt, and increasing the amount of water coming out of the Arctic Ocean. Melting following the peak of the Little Ice Age in the mid 1700s may have triggered an input of freshwater, causing some of the earliest changes that we found, with modern climate change helping to propel those changes beyond the natural variability of the Holocene.

We still don’t know what has ultimately caused these changes in ocean circulation. But it does seem that the ocean is more sensitive to modern climate changes than previously thought, and we will have to adapt.

The Case for Climate Pessimism

Kena Betancur/Getty Images

A frightening report on climate change has some experts pondering the perils of optimism about the future.

Carbon Dioxide Reached a New High in Humanity’s Existence

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Illustration for article titled Carbon Dioxide Reached a New High in Humanitys Existence
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We’re not even through the first month of 2020, and we already broke the record for the day with the most carbon dioxide in all of human history.

Carbon dioxide in Earth’s atmosphere hit 415.79 parts per million (ppm) at Mauna Loa Observatory on Tuesday. It’s not surprising carbon dioxide levels hit a new daily high, but the new atmospheric record underscores the fact that carbon emissions are rising to new all-time highs when they need to be dropping.

Atmospheric carbon dioxide follow seesaw pattern over the course of a year, rising from fall into spring as plants decay and then declining over the summer as plants grow and suck carbon out of the atmosphere. The cycle has been driven by natural processes for all of human existence until the world began emitting carbon dioxide. Now, the seesaw still exists but it’s been steadily rising with each passing year of continued carbon emissions. The daily record on Tuesday recorded at Mauna Loa Observatory, the gold standard of measuring sites, is an indicator of more records to come in the next few months. The monthly carbon dioxide record is usually set in March or April, though last year’s happened in February owing to human activities that burn fossil fuels.

Scientists can take a long view of carbon dioxide by looking at air trapped in ice cores to understand what the atmosphere of the past looked like. Those record stretch back 800,000 years, as long as humans have walked the Earth. For most of those 800,000 years, average carbon dioxide levels stayed beneath 280 ppm. Things started changing quickly during the industrial era, when humans started burning fossil fuels. The atmosphere humanity has created to day pre-dates our very existence by millions of years.

Despite the clear risks a more carbon dioxide-laden atmosphere poses, emissions are rising faster and faster. As long as humans continue emitting carbon, we’re guaranteed to keep setting new milestones. Just last May, we crossed 415 ppm for the first time ever. That record topped the previous one, which we hit just three months prior. We never even crossed 400 ppm before 2015.

All this carbon is heating up the planet, which is increasing the odds and intensity of heat waveswildfiresstorms and floods. It’s also ruining our air quality, causing public health crises, and even making it harder to think. All the while, science continues to show the risks have never been clearer of what will happen if humanity keeps emitting carbon.

Researchers warn that we’re approaching key tipping points that can trigger runaway global warming and fundamentally disrupt the planet’s climate system. Old Arctic sea ice is on the brink of disappearing. On land, massive ice sheets in Antarctica face the risk of unstoppable collapse and could raise sea levels 10 feet or more. And as forest become more prone to burning, some are beginning to emit carbon and worsening the climate crisis. All this, combined with continued carbon emissions, means we’re headed for even more climate devastation.

We can still change that. It will take radical changes to the global economy, which won’t be easy. But the alternative is complete catastrophe.

Greta Thunberg hits back after Mnuchin says she should study economics at college

KEY POINTS
  • “My gap year ends in August, but it doesn’t take a college degree in economics to realise that our remaining 1,5° carbon budget and ongoing fossil fuel subsidies and investments don’t add up,” the 17-year-old said via Twitter.
  • Her comments come shortly after Treasury Secretary Steven Mnuchin criticized her financial credentials at the World Economic Forum.
  • Thunberg, alongside 20 other young climate activists, had called on the world’s decision-makers and business leaders to stop all investments in fossil fuel exploration and extraction.
VIDEO01:35
Mnuchin criticizes climate activist Greta Thunberg: ‘Who is she?’

DAVOS, Switzerland — Swedish climate activist Greta Thunberg hit back at Steven Mnuchin on Thursday, after the Treasury Secretary suggested she needed to study economics at college before lecturing the U.S. on fossil fuel investments.

“My gap year ends in August, but it doesn’t take a college degree in economics to realise that our remaining 1,5° carbon budget and ongoing fossil fuel subsidies and investments don’t add up,” the 17-year-old said via Twitter.

“So either you tell us how to achieve this mitigation or explain to future generations and those already affected by the climate emergency why we should abandon our climate commitments,” she added.

Greta Thunberg

@GretaThunberg

My gap year ends in August, but it doesn’t take a college degree in economics to realise that our remaining 1,5° carbon budget and ongoing fossil fuel subsidies and investments don’t add up. 1/3

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Mnuchin had criticized Thunberg’s financial credentials at the World Economic Forum earlier in the day.

Speaking to reporters during a press briefing, Mnuchin was asked whether the world’s largest economy should completely and immediately divest from fossil fuels.

GP: SWITZERLAND-POLITICS-ECONOMY-DIPLOMACY-WEF-ENVIRONMENT-CLIMATE 200123 EU
Swedish climate activist Greta Thunberg attends a session at the Congres center during the World Economic Forum (WEF) annual meeting in Davos, on January 21, 2020.
FABRICE COFFRINI | AFP via Getty Images

That’s because Thunberg, alongside 20 other young climate activists, had called on the world’s decision-makers and business leaders to stop all investments in fossil fuel exploration and extraction.

“Is she the chief economist or who is she? I’m confused,” Mnuchin said, before adding this was “a joke. That was funny.”

“After she goes and studies economics in college she can come back and explain that to us,” Mnuchin said.

Carbon budget

An intensifying climate crisis is top of the agenda in Davos, Switzerland.

It follows a 12-month period that saw the hottest year on record for the world’s oceans, the second-hottest year for global average temperatures and wildfires from the U.S. to the Amazon to Australia.

VIDEO04:26
Steven Mnuchin addresses his comments about environmental activist Greta Thunberg

Earlier in the week, Thunberg cited the International Panel on Climate Change report from 2018 as she delivered remarks to a packed audience.

The IPCC report states the remaining carbon budget would need to fall below 570 gigatons of carbon dioxide in the coming years if the world is to have a 67% chance of limiting global warming to 1.5 degrees Celsius.

“With today’s emissions levels, the remaining budget is gone in less than eight years,” Thunberg said Tuesday. “These aren’t anyone’s views. This is the science.”

Thunberg was catapulted to fame for skipping school every Friday to hold a weekly vigil outside the Swedish Parliament in 2018.

It sparked an international wave of school strikes — also known as “Fridays for Future” — with millions of children taking part in rallies around the world.

US environmental policies are ‘misunderstood’

When asked to address his comments about Thunberg on CNBC’s “Squawk Box” on Thursday, Mnuchin said: “Let me just comment because obviously the climate issue is something that is being talked about this week.”

“And I think, quite frankly, our environmental policies are misunderstood. The president absolutely believes in clean air and clean water. He supports a clean environment.”

President Donald Trump has often expressed skepticism about the scale of the climate crisis and on Tuesday, he urged participants of the forum to reject the “perennial prophets of doom.”

The U.S. president did not name anyone directly during his speech, but he did encourage those in attendance to ignore environmental “alarmists” and their “predictions of the apocalypse.”

Since coming to power in 2016, Trump has taken steps to pull the U.S. — one of the world’s leading carbon emitters — out of the Paris Agreement and sought to roll back over 80 environmental regulations.

“If you look at the real environmental issues right now, they are in China, they are in India. If you look at what the U.S. has been doing on its own, without government intervention, industry has gotten a lot more efficient on carbon emissions,” Mnuchin said.