Global warming is driving leafy tropical canopies close to temperatures where they can no longer transform sunlight and CO2 into energy, threatening total collapse if the thermometer keeps climbing, according to a study Thursday.
A tiny percentage of upper canopy leaves have already crossed that threshold, reaching temperatures so high -- above 47 degrees Celsius -- as to prevent photosynthesis, the study published in Nature reported.
Currently, some leaves exceed such critical temperatures only 0.01 percent of the time, but impacts could quickly scale up because leaves warm faster than air, the researchers said.
"You heat the air by two to three degrees and the actual upper temperature of these leaves goes up by eight degrees," lead author Christopher Doughty of Northern Arizona University told journalists.
If tropical forest's average surface temperature warms 4C above current levels -- widely considered a worst-case scenario -- "we're predicting possible total leaf death," he said.
The new research suggests that leaf death could become a new factor in the predicted "tipping point" whereby tropical forests transition due to climate change and deforestation into savannah-like landscapes.
If air temperatures increase unabated by 0.03 C per year, the study projected, mass mortality among the canopies could happen in a little more than a century.
Doughty and his team used data from the NASA ECOSTRESS satellite -- designed to measure plant temperatures -- validated with ground observations, based in part on sensors attached to individual leaves.
- Increased tree death -
There remain uncertainties as to how high leaf temperatures might impact the forest as a whole, the scientists cautioned.
"Believe it or not, we don't know terribly much about why trees die," said co-author Gregory Goldsmith of Chapman University.
It doesn't take a scientist to know that when a tree loses its roots it dies, he said.
But the interactions and feedbacks between heat and drought -- and water and temperature -- on overall tree health aren't as clear.
Total leaf death might not necessarily mean total tree death.
The critical temperature at which leaves turn brown and die might also differ by species, depending on the size and thickness of their leaves and the breadth of their canopy.
But there are already concerning signs. In the Amazon, where temperatures are higher than in other tropical forests, the rate at which trees are dying has increased in recent decades.
"The Amazon is currently experiencing higher levels of mortality than Central Africa and that could possibly be due to the high temperatures we've seen there," said Doughty.
Increased fragmentation of the forests from deforestation has also been shown to make the remaining forest areas warmer.
Tropical biomes contain 45 percent of the Earth's forests, and play an outsized role in absorbing human-caused carbon pollution.
They also harbour half or more of the world's plant biodiversity, with at least 40,000 different tree species, according to the Intergovernmental Panel on Climate Change (IPCC).
The fact that a few leaves are overheating at current temperatures is a "canary in the coal mine," said senior author Joshua Fisher of Chapman University.
"You want to be able to detect something happening before it's widespread," he said.
"The fact that we can do that now gives us that ability to actual
ly do something as a collective society."
Scientists not involved in the study said it should serve as a warning that nature's capacity to adapt to climate change has limits.
"It is true that trees and other kinds of vegetation can soak up emissions and provide cooling," commented Leslie Mabon, a lecturer in environmental systems at The Open University.
"However, this study illustrates that without concerted action by humans to reduce emissions and limit global heating at the same time as protecting and enhancing nature, some functions of nature may start to break down at higher temperatures."
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TotalEnergies
Artificial Intelligence Analysis
Defense Industry Analyst:
8/10
Stock Market Analyst:
6/10
General Industry Analyst:
7/10
Analyst Summary
:
A new study published in Nature suggests that global warming is driving tropical canopies toward temperatures that could prevent photosynthesis, threatening total collapse if the thermometer continues to climb. The study found that current temperatures exceed the critical threshold of 47 degrees Celsius only 0.01 percent of the time, but if temperatures increase 4C from current levels, mass mortality among the canopies could happen in a little more than a century. The research provides further evidence of how climate change is impacting the worlds tropical forests, which play a crucial role in the global carbon cycle. Analysts should consider the implications of this study for the defense industry, stock market, and general industry.Over the past 25 years, defense, stock market, and general industry have seen a significant shift in the way they handle climate change. In defense, countries have begun to invest in renewable energy sources and climate-friendly technology, while the stock market has seen an influx of investments in green technology and companies that are making efforts to reduce their carbon footprint. Meanwhile, the general industry has seen a rise in environmental regulations and an increased focus on sustainability. These trends have been in response to the growing awareness of the effects of climate change and the need to reduce emissions.The new study provides further evidence of the impact of climate change on the world’s tropical forests and the implications this has for the defense industry, stock market, and general industry. It is clear that the defense industry needs to continue investing in renewable energy sources and climate-friendly technology, while the stock market should continue to invest in green technology and companies that are making efforts to reduce their carbon footprint. In the general industry, companies should continue to focus on sustainability and make efforts to reduce their emissions.Investigative
Question:
- 1. What are the potential impacts of increased leaf death in the defense industry?
- 2. How could the stock market invest in green technology and companies to reduce their carbon footprint?
- 3.
What strategies can the general industry use to reduce emissions and promote sustainability?4. What other factors could contribute to the tipping point of tropical forests transitioning into savannah-like landscapes?
5. What are some potential solutions to prevent mass mortality among the canopies?
This AI report is generated by a sophisticated prompt to a ChatGPT API. Our editors clean text for presentation, but preserve AI thought for our collective observation. Please comment and ask questions about AI use by Spacedaily. We appreciate your support and contribution to better trade news.
