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New climate warnings in old permafrost

by Bob Berwyn, Inside Climate News 


Highlights

  • A new study in Science Advances says that only a few degrees of warming is needed for large scale permafrost thawing, which would release methane and carbon dioxide that has been trapped in the frost 
  • The permafrost regions of the arctic hold more carbon dioxide than the Earth’s atmosphere. If this carbon is released rapidly in large amounts it will accelerate climate change 
  • This tipping point due to permafrost melt has been seen before in other warming phases of the planet’s history
  • It is uncertain how much of this released carbon could be sequestered by peatlands and new arctic shrubs that have grown due to the warming of that region
  • The melting of permafrost is impacting indigenous peoples in the arctic, as the infrastructure they rely on is built on the collapsing permafrost

Scientists are increasingly warning that to avoid catastrophic impacts from climate change, the world’s governments must implement policies for massive greenhouse gas emissions reductions and begin a drawdown of carbon from the atmosphere within ten years. With 9 of 15 global tipping points now active, what we do today can either unleash an inhospitable hothouse Earth or secure a safe climate well into the future. For a safe and healthy future for all, endorse the Climate-Safe California Platform to implement scalable solutions that can reverse the climate crisis.


Read More: https://insideclimatenews.org/news/16102020/permafrost-study-arctic-ocean-climate-change

New studies show drought and heat waves will kill most trees alive today

By Bob Berwyn, Insideclimate News


Highlights

  • Tim Brodribb, a plant physiologist at the University of Tasmania, published a study that helps identify how trees succumb to heat and dryness
  • The study shows that if climate change continues to persist, most living trees will not be able to survive the warmer climate of the Earth in 40 years
  • Though other research has concluded that more carbon dioxide would result in more plant growth, the negative impacts of warming and drying are already outpacing the fertilization benefits of increased carbon dioxide.
  • Bridribb says the time for action is now:

“We’re at a point where we can see the process, we can predict it. It’s time to start making some noise about it. We can’t afford to sit on our hands.”

  • Since more droughts and higher temperatures are expected, forests globally will continue to be severely impacted with tree deaths
  • The decimation of forests would result in more carbon dioxide in the atmosphere, causing an increase in warming, as well as a loss of animal habitats
  • This new information could damper efforts to plant more trees as a method to sequester carbon since it may become too hot for seeds to sprout 
  • Trees that have survived climate changes and bug infestations will be important in creating new resilient forests

Implementing bold and equitable policies that will catalyze carbon sequestration through building healthy soils and restoring healthy habitats will be key to achieving carbon neutrality by 2030 and net negative emissions by 2035. Endorse The Climate Center’s Climate-Safe California Platform today.


Read more: https://insideclimatenews.org/news/24042020/forest-trees-climate-change-deforestation?

Tropical forests losing ability to absorb CO2, study says

by Daisy Dunne, Carbon Brief, January 27, 2020


Highlights

Tropical forests are losing their ability to capture carbon dioxide from the air due to deforestation. 

  • The boreal forests found in cool temperature, high mountain ranges are sequestering more CO2 than tropical forests due to the rise of the CO2 Fertilization Effect
  • Roughly 30% of all human-caused greenhouse gas emissions are absorbed by the land, creating a “carbon sink” 
  • Carbon was lost in tropical forest regions due to lack of rain

The Climate Center aims to sequester 100+ MMT of additional CO2e per year by 2030 through healthy soils and vegetation management.


Read more: https://www.carbonbrief.org/tropical-forests-losing-ability-to-absorb-co2-study-says

Few pathways to an acceptable climate future without immediate action, e.g., carbon neutral energy production by 2030 and low atmospheric sensitivity to increased CO2

  • A new comprehensive study of climate change has painted over 5 million pictures of humanity’s potential future, and few foretell an Earth that has not severely warmed.
  • But with immediate action and some luck, there are pathways to a tolerable climate future, according to a research team.
  • One pathway is to immediately and aggressively pursue carbon-neutral energy production by 2030 and hope that the atmosphere’s sensitivity to carbon emissions is relatively low, according to the study.
  • The researchers emphasize that rapid carbon reduction strategies provide a hedge against the possibility of high climate sensitivity scenarios.

Read full ScienceDaily summary here (from March 2019)

….The model used in the study accounts for uncertainties in human activity and climate by exploring millions of scenarios, some of which reveal pathways to a world where warming is limited to 2-degrees Celsius by the year 2100 — a goal most climate experts say is required for a “tolerable” future.

The massive analysis shows that meeting that target is exceptionally difficult in all but the most optimistic climate scenarios. One pathway is to immediately and aggressively pursue carbon-neutral energy production by 2030 and hope that the atmosphere’s sensitivity to carbon emissions is relatively low, according to the study. If climate sensitivity is not low, the window to a tolerable future narrows and in some scenarios, may already be closed.

The researchers emphasize that rapid carbon reduction strategies provide a hedge against the possibility of high climate sensitivity scenarios.

“Despite massive uncertainties in a multitude of sectors, human actions are still the driving factor in determining the long-term climate. Uncertainty is sometimes interpreted as an excuse for delaying action. Our research shows that uncertainty can be a solid reason to take immediate action,” said Lamontagne.

J. R. Lamontagne, P. M. Reed, G. Marangoni, K. Keller, G. G. Garner. Robust abatement pathways to tolerable climate futures require immediate global actionNature Climate Change, 2019; DOI: 10.1038/s41558-019-0426-8

Abstract

Disentangling the relative importance of climate change abatement policies from the human–Earth system (HES) uncertainties that determine their performance is challenging because the two are inexorably linked, and the nature of this linkage is dynamic, interactive and metric specific1. Here, we demonstrate an approach to quantify the individual and joint roles that diverse HES uncertainties and our choices in abatement policy play in determining future climate and economic conditions, as simulated by an improved version of the Dynamic Integrated model of Climate and the Economy2,3. Despite wide-ranging HES uncertainties, the growth rate of global abatement (a societal choice) is the primary driver of long-term warming. It is not a question of whether we can limit warming but whether we choose to do so. Our results elucidate important long-term HES dynamics that are often masked by common time-aggregated metrics. Aggressive near-term abatement will be very costly and do little to impact near-term warming. Conversely, the warming that will be experienced by future generations will mostly be driven by earlier abatement actions. We quantify probabilistic abatement pathways to tolerable climate/economic outcomes4,5, conditional on the climate sensitivity to the atmospheric CO2 concentration. Even under optimistic assumptions about the climate sensitivity, pathways to a tolerable climate/economic future are rapidly narrowing.