Effects of Climate Change on the biosphere

[Aporia_filia]

There are zero fish stocks driven to extinction by fishing

Bruce, agreeing with Sidd and Terry I cannot understand your position. As well as industrial farming is destroying the land, industrial fishing is destroying the seas. Where are the tuna, the cod, the Chinook, the whales... Maybe no species has been completely gone extinct, but they have disappeared from where they were usual and became rare.
Even, countries have signed treaties not to overfish, and they are hard to convince.
I saw disappear abundant and varied fishing in the Gulf of Cádiz, just after the first trawler and the first long distance statics nets were used (the first came with a game change for the other fishermen). The "almadrabas" used for fishing tuna were already famous in the Roman Empire. I have dived in them with dozens of tuna fish with a few of them bigger than caws, >500kg, going in circles around me. Nowadays they're lucky if they catch one or two over 200hkg. Mackerels were so abundant! We used to throw off board a mixture of grinded mackerel with its oil and sand and in a few minutes the sea around our boat was silver coloured and you could catch them with a 5 meters line and a couple of hooks with nothing on them.

And there are different ways industrial fishing can be harming.

https://www.latimes.com/nation/la-na-atlantic-salmon-20170903-story.html

http://sportfishing.bc.ca/wp-content/uploads/2018/02/SRKW-Discussion-Paper-Final-Feb-15-2018.pdf

[Sigmetnow]

The Suffolk Owl Sanctuary first thought the bird was injured, but it turns out she was just carrying some extra holiday weight.

'Extremely Obese' Owl Rescued After Becoming Too Fat To Fly

We also found that the area where she was rescued was crawling with field mice and voles due to the warm and wet winter we experienced in December.

https://www.huffpost.com/entry/little-owl-too-fat-to-fly_n_5e322b3bc5b611ac94cf2e20

[Tom_Mazanec]

^^
Good to know that even wise owls have difficulty like I do resisting the temptation to overeat!

[kassy]

The megabiota are disproportionately important for biosphere functioning

Abstract
A prominent signal of the Anthropocene is the extinction and population reduction of the megabiota—the largest animals and plants on the planet. However, we lack a predictive framework for the sensitivity of megabiota during times of rapid global change and how they impact the functioning of ecosystems and the biosphere. Here, we extend metabolic scaling theory and use global simulation models to demonstrate that (i) megabiota are more prone to extinction due to human land use, hunting, and climate change; (ii) loss of megabiota has a negative impact on ecosystem metabolism and functioning; and (iii) their reduction has and will continue to significantly decrease biosphere functioning. Global simulations show that continued loss of large animals alone could lead to a 44%, 18% and 92% reduction in terrestrial heterotrophic biomass, metabolism, and fertility respectively. Our findings suggest that policies that emphasize the promotion of large trees and animals will have disproportionate impact on biodiversity, ecosystem processes, and climate mitigation.

Whole paper:
https://www.nature.com/articles/s41467-020-14369-y

[Niall Dollard]

Increased greening of the World since the 1980s is estimated here to have cut back global temperatures by about 0.2 C.

In other words we would be 0.2 C warmer already without the extra plant life. Shows us how difficult it would be to bring down global temperatures, in the next few centuries.

https://earthobservatory.nasa.gov/images/146296/global-green-up-slows-warming?utm=carousel

[Sigmetnow]

Great Barrier Reef corals begin to bleach amid rising concerns of reef's health

Corals in the far north of the Great Barrier Reef have started to bleach, leaving the federal government's lead reef agency at a state of "heightened alert" about the prospect of a mass bleaching event unfolding over the next two to four weeks.

David Wachenfeld, chief scientist of the Great Barrier Reef Marine Park Authority, said survey teams had found "significant bleaching" at three reefs in the Shelburne Bay/Wuthani region of Cape York in the far north.

However, with most of the Great Barrier Reef park now at two to three degrees above normal, the heat stress on corals that causes bleaching and possible death is rapidly mounting in many regions, Dr Wachenfeld said.

The current forecasts for the next few weeks "are giving us a heightened risk of a mass bleaching event", he said, adding the threat may peak in the second week of March or later.

While the arrival of widespread rain, thunderstorms or a cyclone could disrupt that build-up of heat, meteorologists are not predicting any major weather event, Dr Wachenfeld said.
 ...

https://amp.smh.com.au/environment/climate-change/concerns-rise-for-great-barrier-reef-health-as-corals-start-to-bleach-20200220-p542lx.html

[Sigmetnow]

Bears are waking up — because it’s too warm, too soon

Europe just had its warmest winter ever, the US has just had its hottest December and January on record — and as a result, the bears are waking up from hibernation early because they think it’s spring.

According to the Guardian, there have been bear sightings in February and early March in Russia, Finland, Canada, and the US. In Banff in Canada, a grizzly bear was spotted on March 3, and in Yellowstone Park in the US, another grizzly was seen on March 7.

According to Yellowstone’s website, male grizzlies normally come out of hibernation in mid- to late March, and females with cubs emerge later, in April to early May.

So why is this early emergence of the bears a problem? Because if they wake up too early, there isn’t enough of their omnivorous diet for them to eat. And if they don’t have enough to eat, they go in search of food, where a run-in with humans is a possibility as they rifle through garbage and gardens.

Chris Servheen, a former grizzly bear recovery coordinator at the US Fish and Wildlife Service, said:
If we see this as a continuing thing with climate change we will probably see more conflicts because there’s not much food for the bears. If bears come out early they will potentially seek food around people, such as in garbage, bird feeders and crops. The potential for conflict is certainly higher as they come out earlier.

https://electrek.co/2020/03/14/climate-crisis-weekly-bears-hibernation-warm-greta-thunberg-new-york-city-cycling/