UnSubRocky wrote on Apr 8^th, 2023 at 5:29pm:



Not in Australia.

Belgarion wrote on Apr 8^th, 2023 at 5:49pm:


About 320ppm be good. Milder climate than now, melting of land ice be a lot slower than now. Higher sea levels would help moderate climate—if this happens slowly populations and infrastructure etc could be moved to higher altitudes.

Methane in the atmosphere had its fourth-highest annual increase in 2022, the National Oceanic and Atmospheric Administration reported, part of an overall rise in planet-warming greenhouse gases that the agency called “alarming.”

Though carbon dioxide typically gets more attention for its role in climate change, scientists are particularly concerned about methane because it traps much more heat — about 87 times more than carbon dioxide on a 20-year timescale.

[quote]

More CO2 in the atmosphere hurts key plants and crops more than it helps

. . .you may have heard a myth that nature’s balance doesn’t really matter. After all, CO2 is natural, and it helps plants and crops grow. That’s true. But it’s also misleading in that it’s only part of the story. A widely circulated myth suggests that adding extra CO2 to the atmosphere will fertilize plants and crops and make the world greener and better. Unfortunately, that turns out not to be true. . . .

The myth that CO2 is plant food and that “extra” CO2 therefore can’t be bad is an example of a logical fallacy. It sort of sounds right, but it’s a major oversimplification. It’s appealing because it suggests that it’s okay to emit the pollution that causes climate change. But the myth is not true.

A lot of myths have a grain of truth to them. That’s part of what makes them believable – at first. But it’s up to us to look beyond that single fragment of a fact. In the case of the CO2-as-fertilizer myth, you can test the idea by thinking about your own garden. Is fertilizer alone sufficient to create a healthy garden? Of course not. A garden needs the right amount of water, stable weather conditions, and plants that are suited to the local environment. These are the same factors that have been disrupted by an overload of CO2 in the atmosphere. For example, just adding more fertilizer doesn’t help plants when a garden is getting either too much or not enough water.

Nature is like a recipe, with each ingredient needed in just the right measure. A pinch of nutmeg gives pumpkin pie a rich, warm flavor, but a tablespoon of nutmeg would ruin the pie. A car’s engine runs on a precise blend of air, fuel, and spark. Overloading one element disrupts the whole system. Many aspects of nature operate in a similarly balanced way.

For example, the atmosphere has a specific recipe. CO2 and other greenhouse gases are an essential part of the recipe because they trap heat in the atmosphere. With no CO2 Planet Earth would be in a perpetual ice age. But a small amount of CO2 keeps the planet in the famous “Goldilocks and the Three Bears” condition: not too hot, not too cold, but the “just right” zone that’s ideal for life as we know it. Too much CO2 overheats the planet.

By studying Earth’s history, scientists have learned that when there was a lot of CO2 in the atmosphere, the planet was hot. In fact, the last time the Earth had as much CO2 in the atmosphere as it now does was the Pliocene Epoch, more than 3 million years ago. At that time, Earth’s atmosphere was 3.6 to 7.2 degrees Fahrenheit warmer (2 to 4 degrees Celsius) than it is today. And global sea level was 50 to 80 feet (15 to 25 meters) higher.

Climate change is hard on plants.
The basics of climate change are actually easy to understand. Human activities emit around 100 million tons of CO2 every day, mostly by burning fossil fuels, which causes the atmosphere to trap more heat. As a result of that heat-trapping pollution, the atmosphere, land, and oceans have all become warmer. The added heat triggers side effects like more intense rainstorms, floods, prolonged heat waves, and droughts. In turn, those unpleasant conditions lead to more frequent and severe wildfires, insect outbreaks, and crop failures. Sure, today’s plants have a bit more fertilizer from the extra CO2 in the air, but that additional CO2 causes many other problems, harming many plants and crops. Climate change is disrupting plant growth.


Scientists have performed many experiments to see what happens when plants and agricultural crops receive extra CO2. When supplemental CO2 was pumped into the air around plants, they grew faster. For this reason, CO2 is sometimes piped into enclosed greenhouses to boost production. But greenhouse plants also have optimal amounts of water, excellent soil, and controlled temperatures. It’s usually a different story out in the real world.

To conduct a more “real world” experiment, other studies have given plants extra CO2 plus an increase in temperature. In these conditions, many plants and crops grew poorly. In most cases, the boost from CO2 was overwhelmed by the hotter conditions. These experiments demonstrate that the myth of CO2 fertilization is false, and peer-reviewed reports find that major crops like wheat, rice, corn, and soybeans will become less productive as the world heats up.

Likewise, a landmark study in 2018 found that growing rice in high-CO2 conditions makes it less nutritious. As a basic grain, rice plays a critical role in feeding the world’s population. The extra CO2 caused an imbalance within the crop’s chemical makeup, which resulted in rice that had lower amounts of protein, iron, zinc, and B-vitamins. “The entire elemental balance is out of whack,” explained plant physiologist Lewis Ziska, an author of the study. This result is yet another example of how the recipe of nature is being disrupted by excess CO2.

Cancer-causing pollution
Air pollution causes millions of deaths worldwide each year, including more than 250,000 from a type of lung cancer called adenocarcinoma. But it has been difficult to investigate how air pollution triggers cancer, in part because its effects are less pronounced than those of better-studied carcinogens such as tobacco smoke or ultraviolet light, says Nik-Zainal.

To unpick the mechanism, cancer researcher Charles Swanton at the Francis Crick Institute in London and his colleagues mined environmental and
epidemiological data from the United Kingdom, Canada, South Korea and Taiwan. To diminish the contribution of tobacco smoke to the data, the team focused on lung cancers that carried mutations in a gene called EGFR. These mutations are more common in lung cancers in people who have never smoked than in those in smokers.

The team found that lung cancers bearing EGFR mutations were associated with exposure to air pollution in the form of inhalable particles with a diameter of 2.5 micrometres or less — less than one-tenth the width of the average grain of pollen. Such pollution is emitted by internal combustion engines, coal-fired power stations and burning wood.

A podcast. Have not listened to this myself yet.

https://theconversation.com/fear-and-wonder-podcast-how-scientists-attribute-ext...