by TAN tax
Similar posts from New Zealand and France included a 37-second video clip of an interview with Princeton University physics professor William Happer, broadcast by Sky News Australia in September 2023.
Happer, who was a science adviser to former US president Donald Trump, said in the interview: “More CO2 is good for the world. It’s not bad for the world. And so it’s absurd to want to reduce CO2 decrease.”
“We have a CO2 famine now, compared to what plants are used to. And just about any plant, if you give it more CO2 and more, it will do better,” he said.
In response to an inquiry from AFP, Professor Happer said he stood by his comments.
“The clearest evidence that the Earth is CO2 starved, compared to what most plants would prefer, is that flower, fruit and vegetable growers continue to pay the substantial costs of tripling or quadrupling on CO2 concentrations in their greenhouses,” he said. .
However, multiple climate scientists told AFP that the world is in no danger of a “CO2 famine” and quite the opposite is happening. They said CO2 levels – mainly from humans burning fossil fuels – are increasing at a rate unprecedented since pre-industrial times.
Scientific consensus
“We are a long way from any CO2 famine,” Howard Diamond, senior climate scientist at the US National Oceanic and Atmospheric Administration (NOAA) told AFP on February 13, 2024 (archived link).
Pelle Boberg, a climate analyst at the Swedish Environmental Protection Agency, said separately on February 15: “The opposite problem is that the amount of carbon dioxide in the atmosphere is growing rapidly” (archive link).
“Carbon dioxide levels have varied greatly over time, and life on Earth has adapted to it,” Boberg explained. But the pace at which CO2 is currently increasing “is happening so fast that it is becoming increasingly difficult for ecosystems to keep up with it”.
According to a report issued by the United Nations Intergovernmental Panel on Climate Change (IPCC) in 2021: “The evidence is clear that carbon dioxide (CO2) is the main driver of climate change, even as greenhouse gases other heat and air pollutants also affect the climate. ” (link in archive).
Limiting global warming is critical to avoiding a long-term planetary climate catastrophe, the report’s authors wrote.
“In the case of 1.5C of global warming, heat waves will increase, hot seasons will be longer and cold seasons will be shorter,” they said. “At 2C of global warming, heat extremes would often reach critical tolerance thresholds for agriculture and health.”
The IPCC report represents a global scientific consensus on the issue.
‘Pre-post’ chart details
The chart shared several times online was also inaccurate, experts said.
Diamond from NOAA said the chart shows the planet hovering near a The “line of death” was “quite preposterous and not consistent with science or any of the data we have”.
He explained that ice core data — samples that enable scientists to estimate past climate — found a cycle of about 180 to 290 ppm of CO2 over the past 800,000 years.
That level was less than the current CO2 concentration of about 420 ppm but “living organisms did fine” Diamond said.
He also cited a graph in a 2017 paper published in Nature Communications, showing CO2 levels over the past 420 million years and setting this in the context of projected future change (archived version).
The graph included estimates of CO2 levels over the next few centuries, based on various future emission scenarios by the IPCC, showing that levels will reach peaks not seen in millions of years.
The paper said that unabated fossil fuel use could lead to a situation where CO2 continues to rise”without geological precedent in the last half billion years”.
Below is a screenshot of the graph found in the paper:
Plant life
Claims that increased levels of CO2 are beneficial to plants also leave an important context.
Plants use sunlight to convert CO2 into an energy source in a process called photosynthesis. Experts said increased CO2 levels could, to some extent, stimulate plant growth.
But Antoine Martin, a senior scientist from the Montpellier Institute of Plant Sciences told AFP other factors counterbalance the effect of increased CO2.
“If we increase the amount of carbon dioxide, we know that the nutrients (nitrogen, phosphorus, etc.) must be supplied in a slightly larger quantity to stimulate photosynthesis.,” he said.
These nutrients are not necessarily present in sufficient quantities to support plant growth due to additional CO2.
“T istomore is better’ philosophy is not how things work in the real world,” Diamond said.
The chart circulating online misleadingly showed that CO2 levels from about 100 million years ago — between 1,000 and 1,500 ppm — were “best for plants”.
“Since agriculture developed in conjunction with the development of human civilization and about 20,000 years ago, the CO2 levels were in the low to mid 200 ppm, so I would not say that a level of 1000–1500 ppm is optimal,” A Diamond said.
The effects of a warming planet also affect plant life, according to scientists.
“CO2 is a greenhouse gas, it causes climate change whose effects include global warming, melting ice, rising sea levels,” Ranga Myneni, climate professor at Boston University told AFP on December 13, 2023 (archive link).
“During the summer, the temperature problem is increasing, and especially periods of drought that create water stress reducing the productivity of forests or even killing trees,” said Nicolas Viovy, a researcher at the French Laboratory of Climate and Environmental Sciences (LSCE) (archive link).
“I’m talking about trees but the problem is also found in crops.”
AFP has repeatedly debunked misinformation about the climate crisis here.
