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Investors urge heavy carbon emitters to set science-based reduction targets

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FILE PHOTO: Cracked earth marks a dried-up area near a wind turbine used to generate electricity at a wind farm in Guazhou, 950km (590 miles) northwest of Lanzhou, Gansu Province September 15, 2013. REUTERS/Carlos Barria/File Photo

LONDON (Reuters) – Investors managing around $20 trillion in assets on Tuesday called on the heaviest corporate emitters of greenhouse gases to set science-based targets on the way to net zero carbon emissions by mid-century.

AXA Group and Nikko Asset Management Co are among 137 investors urging 1,800 companies responsible for a quarter of global emissions to act, coordinated by non-profit group CDP.

While more companies are pledging their support for the 2015 Paris agreement on climate change, aiming to be carbon neutral by 2050, not all have been clear about how they will get there.

To help limit global warming to no more than 1.5 degrees Celsius above pre-industrial norms by 2050, companies need to set out their pathway to net zero and ensure it is consistent with the science and independently verified, the investors said.

“Climate change presents material risks to investments, and companies that are failing to set targets grounded in science risk losing out – and causing greater damage to the world economy,” said Emily Kreps, Global Director of Capital Markets at CDP.

The companies targeted together annually contribute 13.5 gigatonnes of emissions directly and indirectly tied to their operations, equivalent to 25% of the world’s total, CDP said.

Specifically, the investors said they wanted companies to set targets through the Science-Based Targets Initiative to help ensure the goals can be more easily compared and assessed.

More than 1,000 companies have already set science-based targets, of which around 300 have targets in line with the 1.5 degrees goal.

“Companies that do not set science-based targets risk being surprised by increased

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As atmospheric carbon rises, so do rivers, adding to flooding

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flood
Credit: CC0 Public Domain

When it comes to climate change, relationships are everything. That’s a key takeaway of a new UO study that examines the interaction between plants, atmospheric carbon dioxide and rising water levels in the Mississippi River.


Published recently in the Geological Society of America’s journal GSA Today, the study compared historical atmospheric carbon data against observations of herbarium leaf specimens to quantify the relationship between rising carbon levels and increasingly catastrophic floods in the American Midwest.

Using data covering more than two centuries, researchers demonstrated that as carbon levels in the atmosphere have risen due to the burning of fossil fuels, the ability of plants to absorb water from the air has decreased. That means more rainfall makes its way into rivers and streams, adding to their potential for damaging floods.

Co-authored by UO Museum of Natural and Cultural History geologist Greg Retallack and earth sciences graduate student Gisele Conde, the study focused on Ginkgo biloba leaf specimens representing a time span of just over 260 years.

The team examined the leaves’ stomata, tiny pores that deciduous plants use to take up carbon dioxide from the atmosphere. In low-carbon environments, plants increase the density of stomata so they can take in enough carbon dioxide for photosynthesis, but they need relatively few stomata in carbon-rich environments.

“Variations in stomatal density, which we observed using microscopic imaging, reflect corresponding changes in atmospheric carbon over the 264-year span,” said Retallack, director of the museum’s Condon Fossil Collection and a professor of earth sciences.

Stomatal density also governs the degree of transpiration, the process by which plants absorb water and give off water vapor; the fewer the stomata, the lower the transpiration potential. In the leaf specimens under examination, the researchers observed an overall decline in stomatal density and transpiration

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Lidar study suggests carbon storage losses greater than thought in Amazon due to losses at edge of forests

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LiDAR study suggests carbon storage losses greater than thought in Amazon due to losses at edge of forests
Graphic summary of the main results found in the work. Credit: Celso H. L. Silva Junior

An international team of researchers has found that carbon sequestering losses in the Amazon basin have been undermeasured due to omission of data representing losses at the edges of forests. In their paper published in the journal Science Advances, the group describes using lidar to estimate the carbon sequestering abilities of trees along the edges of Amazon forests.


Prior research has shown that when part of a forest in the Amazon basin is cut down, the trees that remain at the edges of the forest are not as robust as those that are situated farther in. This is because they are more exposed to pollution, pesticides, herbicides, etc. In this new effort, the researchers noticed that the reduced sequestering abilities of such trees are not included in studies of carbon sequestering losses in the Amazon basin when deforestation occurs. They suspected such losses are greater than previously thought, as evidenced by large amounts of fragmenting in the Amazon—where forest patches are surrounded by farmlands, much edging occurs.

To find out how much carbon sequestering loss has been occurring in the Amazon, the researchers flew multiple missions above the canopy edges in airplanes with lidar guns aimed downward. The technology is able to determine how healthy trees are by measuring their greenness, and thus how much carbon they are able to absorb. Back on the ground, they fed the data from the lidar guns to software applications with data describing the amount of edge forest in the Amazon basin. The software used the data from the lidar to calculate the degree of the area’s sequestering loss in total over the years 2000 to 2015—947 million tons of carbon. The researchers note that this amount

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Increasing stability decreases ocean productivity, reduces carbon burial

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Increasing stability decreases ocean productivity, reduces carbon burial
Warming ocean surfaces will decrease the oxygen in the upper oceans and decrease bioproductivity, impacting the food source for dolphins and others that rely on fish and sea life. Credit: NOAA

As the globe warms, the atmosphere is becoming more unstable, but the oceans are becoming more stable, according to an international team of climate scientists, who say that the increase in stability is greater than predicted and a stable ocean will absorb less carbon and be less productive.


Stable conditions in the atmosphere favor fair weather. However, when the ocean is stable, the layers of the ocean do not mix. Cooler, oxygenated water from beneath does not rise up and deliver oxygen and nutrients to waters near the surface, and warm surface water does not absorb carbon dioxide and bury it at depth.

“The same process, global warming, is both making the atmosphere less stable and the oceans more stable,” said Michael Mann, distinguished professor of atmospheric sciences and director of the Earth System Science Center at Penn State. “Water near the ocean’s surface is warming faster than the water below. That makes the oceans become more stable.”

Just as hot air rises, as is seen in the formation of towering clouds, hot water rises as well because it is less dense than cold water. If the hottest water is on top, vertical mixing in the oceans slows. Also, melting ice from various glaciers introduces fresh water into the upper layers of the oceans. Fresh water is less dense than salt water and so it tends to remain on the surface as well. Both elevated temperature and salinity cause greater ocean stratification and less ocean mixing.

“The ability of the oceans to bury heat from the atmosphere and mitigate global warming is made more difficult when the ocean becomes