Tag Archives: #GCP

Pandemic Brings Record Fall in Global CO2 Emissions (Nature)

The Global Carbon Project, of which LMU geographer Julia Pongratz is a leading member, reports an unprecedented drop in the level of carbon emissions since the onset of the coronavirus pandemic, although the overall concentration of CO2 in the atmosphere continues to rise.

In the USA and the EU reductions in the use of coal were complemented by the effects of the restrictions imposed in response to the coronavirus pandemic. Photo: imago images / Sven Simon

According to the latest figures published by the Global Carbon Project (GCP), the current coronavirus pandemic has led to a significant reduction in global CO2 emissions. The GCP is an international collaboration of climate researchers, which includes LMU geographers Julia Pongratz, Selma Bultan and Kerstin Hartung as contributors. The group monitors both the amounts of greenhouse gases released into Earth‘s atmosphere and the quantities absorbed by the world’s oceans and sequestered in vegetation on land.

The latest report issued by the GCP shows that, 5 years after the conclusion of the Paris Agreement, the rate of increase in global CO2 emissions has slowed. In the decade from 2010 to 2019, CO2 emissions from fossil sources decreased significantly in 24 countries whose economies had grown over the same period. This result suggests that policies intended to mitigate climate change may be having an effect. Over the course of this year – in part owing to the measures introduced in response to the coronavirus pandemic – global emissions of fossil carbon are estimated to have fallen to 34 billion tons (34 Gt CO2). This figure represents a decrease of some 2.4 Gt from the previous year. This is a considerably larger drop than previous dips in the emission record for the years 1981 and 2009 (0.5 Gt), 1992 (0.7 Gt) and 1945 (0.9 Gt). In order to achieve the goals set out in the Paris Agreement, CO2 emissions must fall by between 1 and 2 Gt annually between now and 2030.

The decrease was particularly notable in the USA (-12%) and in member states of the EU (-11%). “In both cases, reductions in the use of coal were complemented by the effects of the restrictions imposed in response to the coronavirus pandemic,” says Pongratz. “In 2019, the rate of increase in CO2 emissions was slower than in previous years. As a consequence of the pandemic, emissions have now fallen significantly. This makes 2020 a crucial year, but whether it marks the start of a trend strongly depends on how the measures taken to stimulate the economy unfold around the world. We are already seeing signs that the emission rate is climbing back toward the level observed for 2019.”

The transport sector accounts for most of the fall

Most of the decrease recorded for 2020 can be attributed to a drop in the carbon footprint of the transport sector. In December 2020, emissions due to road and air traffic still were lower by about 10% and 40%, respectively, relative to 2019 values. The authors of the report emphasize that it is not yet possible to assess whether the rate of global emissions will continue to fall in the coming years. Following the decrease in emissions in the aftermath of the global financial crisis in 2008, emissions rebounded a massive 5% in 2010, as the global economy recovered. The fear is that this could happen also in 2021.

Overall, total emissions of CO2 – from fossil sources and land use – for 2020 are estimated to be on the order of 39 Gt, which approximately corresponds to the value recorded for the year 2012. This caused the CO2 concentration of the atmosphere to continue rising, and the average concentration for the current year is expected to set a new record of 412 ppm (parts per million). This corresponds to a rise of 48% relative to the pre-industrial level. The authors of the new report point out that the atmospheric CO2 level, and consequently the world’s climate, will only stabilize when global CO2 emissions are near zero.

The overall amount of CO2 absorbed by carbon sinks on land and in the oceans continues to rise, and in 2020, they sequestered some 54% of all anthropogenic CO2 emissions.

No significant decrease in emissions from land use change

Julia Pongratz is particularly interested in the impact of changes in land use on the global carbon balance. While unusually high level of emissions from these sources were estimated for 2019 – which were exacerbated by extraordinarily dry conditions in Indonesia and the highest rate of deforestation in the Amazon Basin since 2008 – the value for 2020 is lower again and equivalent to the mean level for the decade as a whole.

“For the first time, we were able to estimate the gross CO2 emissions and removals through land use changes on the global carbon budget in 2020,” Pongratz says. She and her colleagues come to the conclusion that this factor – largely attributable to deforestation – accounts for the release of around 16 Gt of CO2 per year during the past decade. On the other hand, removals of CO2 such as through the abandonment of agricultural lands, over the same period resulted in an estimated increase of nearly 11 Gt in CO2 sequestration capacity. The net balance of +6 Gt for 2020 is similar to the values for previous years. “We have not found a reduction in carbon emissions in this sector yet. Deforestation continues at a rapid pace, especially in tropical regions, and public awareness of the impact of agricultural emissions has been muted owing to the influence of Covid,” Pongratz says. “Effective measures to improve land management could not only curb deforestation, they could also contribute to an increase in CO2 uptake from the atmosphere by allowing for the regrowth of natural vegetation.”

The team of 86 climate researchers from all parts of the world publishes its study in the peer-reviewed journal Earth System Science Data. The Global Carbon Budget 2020 is the 15th edition of the annual update that started in 2006. Besides Julia Pongratz, Selma Bultan und Kerstin Hartung, scientists from 7 other German institutions contributed — the Alfred-Wegener-Institut (Bremerhaven), the Max Planck Institute for Meteorology (Hamburg), the Max Planck Institute for Biogeochemistry (Jena), the Karlsruhe Institute of Technology, the GEOMAR Helmholtz Centre for Ocean Research (Kiel) and the Leibniz-Institut für Ostseeforschung (Warnemünde).

Further information
Data and Figures 
Data Atlas 
Estimated Daily Emission Rates 

Provided by LMU Munich

Potential Means of Improving Learning and Memory in People With Mental Illnesses (Psychiatry)

More than a dozen drugs are known to treat symptoms such as hallucinations, erratic behaviors, disordered thinking and emotional extremes associated with schizophrenia, bipolar disorder and other severe mental illnesses. But, drug treatments specifically able to target the learning, memory and concentration problems that may accompany such disorders remain elusive.

Average brain activity during a working memory task in a group of healthy subjects as measured by fMRI. The colors represent higher brain activity in the carriers of the G version of the GCPII enzyme, where brains are less efficient at performing the task, compared with those carriers with the A version of the enzyme. ©Bigos laboratory

In an effort to find such treatments, Johns Hopkins Medicine researchers report they have identified a genetic variation in the brain tissue of a subset of deceased people — some with typical mental health and some with schizophrenia or other psychoses — that may influence cognition and IQ. In the process, they unearthed biochemical details about how the gene operates.

Results of their work, described in the Dec. 1 issue of the American Journal of Psychiatry, could advance the development of drugs that target the enzyme made by this gene, and thus improve cognition in some people with serious mental illnesses or other conditions that cause reduced capacity in learning and memory.

Typical antipsychotic medications that treat schizophrenia symptoms regulate the brain chemical dopamine, a transmitter of nerve impulses associated with the ability to feel pleasure, think and plan, which malfunctions in patients with the disorder. However, previous genetic studies have also shown that another brain chemical signal transmitter, glutamate, a so-called “excitatory” chemical associated with learning and memory, plays a role as well. Another so-called neurotransmitter in this process, N-acetyl-aspartyl-glutamate (NAAG), specifically binds to a protein receptor found on brain cells that has been linked to schizophrenia, but how it impacts this disorder is unknown.

The research of clinical pharmacologist Kristin Bigos, Ph.D., assistant professor of medicine at the Johns Hopkins University School of Medicine, sought to explore more deeply the role of NAAG in cognitive impairment with the goal of eventually developing therapies for treating these learning, memory or concentration problems.

Using tissues gathered from a repository of brains from deceased donors belonging to the Lieber Institute for Brain Development, Bigos and her team measured and compared levels of certain genetic products in the brains of 175 people who had schizophrenia and the brains of 237 typical controls.

Bigos and her colleagues specifically looked at the gene that makes an enzyme known as glutamate carboxypeptidase II (GCPII), which breaks down NAAG into its component parts ? NAA and glutamate. In the brains of people with schizophrenia and in the typical controls, they found that carriers of this genetic variant (having one or two copies of the gene variation) had higher levels of the genetic product that makes the GCPII enzyme.

In the gene for the enzyme, the only difference in the versions was a single letter of the genetic code, either G or A (for the nucleotide bases guanine and adenine). If people had the version of the gene with one copy of G, then the tissue at the front of their brain ? the seat of cognition ? had 10.8% higher levels of the enzyme than those who had the version of the gene with A, and if people had two copies, they had 21% higher levels of the enzyme.

To see if this genetic variation in GCPII controlled the levels of NAAG in the brains of living people, the researchers measured levels of NAAG in the brain using magnetic resonance spectroscopy, which uses a combination of strong magnetic field and radio waves to measure the quantity of a chemical in a tissue or organ.

In this experiment, they focused on 65 people without psychosis and 57 patients diagnosed with recent onset of psychosis, meaning many of them were likely to eventually be diagnosed with schizophrenia, at the Johns Hopkins Schizophrenia Center. Participants averaged 24 years of age, and 59% were men. About 64% of participants identified as African American, and the remaining 36% were white.

The researchers found 20% lower levels of NAAG in the left centrum semiovale — a region of the brain found deep inside the upper left side of the head — in the white participants both with and without psychosis who had two copies of the G version of the enzyme compared with other white people who had the A version.

To see if having the G or A version of the gene plays a role in cognition, the researchers tested IQ and visual memory in the healthy participants and those with psychosis, both white and African American. They found that people with the most NAAG in their brain (in the top 25%) scored 10% higher on the visual memory test than those in the bottom 25%. They also found that people with two copies of the G version of the GCPII sequence scored 10 points lower on their IQ test on average than the people with the A version of the gene, which the researchers say is a meaningful difference in IQ.

Finally, they showed that healthy carriers of the G version of the GCPII sequence had less efficient brain activity during a working memory task, as measured by functional MRI, by at least 20% compared with those people with the A version of the gene.

“Our results suggest that higher levels of the NAAG are associated with better visual and working memory, and that may eventually lead us to develop therapies that specifically raise these levels in people with mental illness and other disorders related to poor memory to see if that can improve cognition,” says Bigos.

Additional authors on the study include Caroline Zink, Peter Barker, Akira Sawa, Min Wang, Andrew Jaffe, Joel Kleinman, Thomas Hyde, Kayla Carta and Marcus van Ginkel of Johns Hopkins Medicine, and Daniel Weinberger, Henry Quillian, William Ulrich, Qiang Chen, Greer Prettyman and Mellissa Giegerich of the Lieber Institute for Brain Development.

This work was supported by the Lieber Institute for Brain Development, the National Institutes of Mental Health (MH092443, MH094268, MH105660 and MH107730) and the National Institute on Drug Abuse (DA040127).

Some patient or volunteer recruitment costs were supported by the Mitsubishi Tanabe Pharma Corporation.

Provided by Johns Hopkins Medicine