Archives quotidiennes :

climate-debate

Will Humanity Ever Reach 2XCO2? Possibly Not

by Dr. Roy Spencer, February 2, 2020 in WUWT

Summary

The Energy Information Agency (EIA) projects a growth in energy-based CO2 emissions of +0.6%/yr through 2050. But translating future emissions into atmospheric CO2 concentration requires a global carbon budget model, and we frequently accept the United Nations reliance on such models to tell us how much CO2 will be in the atmosphere for any given CO2 emissions scenario. Using a simple time-dependent CO2 budget model forced with yearly estimates of anthropogenic CO2 emissions and optimized to match Mauna Loa observations, I show that the EIA emissions projections translate into surprisingly low CO2 concentrations by 2050. In fact, assuming constant CO2 emissions after 2050, the atmospheric CO2 content eventually stabilizes at just under 2XCO2.

Introduction

I have always assumed that we are on track for a doubling of atmospheric CO2 (“2XCO2”), if not 3XCO2 or 4XCO2. After all, humanity’s CO2 emissions continue to increase, and even if they stop increasing, won’t atmospheric CO2 continue to rise?

It turns out, the answer is probably “no”.

The rate at which nature removes CO2 from the atmosphere, and what controls that rate, makes all the difference.

Even if we knew exactly what humanity’s future CO2 emissions were going to be, how much Mother Nature takes out of the atmosphere is seldom discussed or questioned. This is the domain of global carbon cycle models which we seldom hear about. We hear about the improbability of the RCP8.5 concentration scenario (which has gone from “business-as-usual”, to “worst case”, to “impossible”), but not much about how those CO2 concentrations were arrived at from CO2 emissions data.

So, I wanted to address the question, What is the best estimate of atmospheric CO2 concentrations through the end of this century, based upon the latest estimates of future CO2 emissions, and taking into account how much nature has been removing from the atmosphere?

As we produce more and more CO2, the amount of CO2 removed by various biological and geophysical processes also goes up. The history of best estimates of yearly anthropogenic CO2 emissions, combined with the observed rise of atmospheric CO2 at Mauna Loa, Hawaii, tells us a lot about how fast nature adjusts to more CO2.

…

climate and geology, climate-debate

Thwaites Glacier: Why Did The BBC Fail To Mention The Volcanoes Underneath?

by D. Whitehouse, January 29, 2020 in GWPF

Scientists have known for years that subglacial volcanoes and other geothermal “hotspots” are contributing to the melting of the Thwaites Glacier. Why did the BBC fail to mention these facts in its recent report?

 

The International Thwaites Glacier Collaboration is performing some magnificent science, conducting the most ambitious fieldwork ever undertaken at the tip of what is one of the most significant glaciers on Earth. Its melting already contributes 4% of global sea level rise and there are fears that it could become unstable and contribute many metres to global sea level.

The reason for its vulnerability lies in its geology. While most of the glacier is on ground and making its way into the West Antarctic seas, Thwaites lip floats on water allowing warm water to weaken and melt it from beneath. Being one of the most difficult places in the world to reach the scientific collaboration planned for years to transport many tonnes of equipment to the glaciers front. Two weeks ago they announced they had carried out the first warm water borehole through the ice at the point where it lifts off the land and starts to be suspended by the ocean. Image courtesy British Antarctic Survey.

…

biology+acidification, climate-debate

Fungal decisions can affect climate

by American Society of Agronomy, January 31, 2020 in WUWT

…

But fungi don’t just release carbon. They can also store it. For example, environmental stress can cause fungi to strengthen their cell walls. They do so by using organic compounds that contain carbon. These carbon compounds can stay in soils for years to decades or even longer.

…

“We found that where drought stress increased, the amount of fungi that invested more in strengthening cell walls and less in decomposition tended to increase,” says Treseder. In contrast, in more moderate conditions, the reverse occurred. Fungi that decomposed more efficiently became more common.

These findings suggest that fungi might store more carbon as global climate becomes more extreme. On the other hand, they might release more carbon dioxide in moderate climates. “These opposing feedbacks would not have been apparent without examining trade-offs among fungal traits,” says Treseder.

…