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Dr Tom Harris @drtomharris.bsky.social · 12m

With the oceans in so much trouble, not least passing the planetary boundary for ocean acidification and the tipping point for coral reefs, this is an area that deserves a lot of research and consideration.

#climatechange #oceans #ironfertilisation #primaryproductivity #geoengineering #marineCDR

Dr Tom Harris @drtomharris.bsky.social · 12m

The benefits include increased primary productivity, enhanced food webs, prevention of ocean anoxia, promotion of cloud formation for cooling and rain production and carbon capture and sequestration.

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Dr Tom Harris @drtomharris.bsky.social · 12m

New understanding of the processes and the declining health of the oceans may promote the technique for marine biomass regeneration or ocean iron management.

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Dr Tom Harris @drtomharris.bsky.social · 12m

Ocean Iron Fertilisation is a geoengineering technique proposed for the increase in biotic carbon capture over the oceans. It has been trialled in the past but with mixed results.

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Dr Tom Harris @drtomharris.bsky.social · 12m

Iron is the limiting nutrient at the very base of the ocean food web. It enables photosynthesis, is essential for all marine life and enables significant carbon capture. Fisheries, whaling and pollution reduce the available iron for these vital processes.
drtomharris.substack.com/p/paying-the...

Paying the Iron Price

Iron is a critical part of life in the oceans. It's a limiting nutrient for primary production which sits at the base of the food chain and absorbs CO2 from the atmosphere. Should we be adding more?

drtomharris.substack.com

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Dr Tom Harris @drtomharris.bsky.social · 1d

We now know tipping points are not obscure academic curiosities, but real thresholds that change the Earth forever. Urgent, coordinated efforts are crucial to mitigate these drivers and to prevent irreversible ecosystem damage.

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Dr Tom Harris @drtomharris.bsky.social · 1d

The escalating fire occurrence, something which is not a natural phenomena in a tropical moist rainforest, is driven by climate change and unsustainable land use. This, along with continuing rises in temperature threatens to push the Amazon towards its catastrophic tipping point.

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Dr Tom Harris @drtomharris.bsky.social · 1d

As a result fires, up by 400%, contributed to a surge of 152% in destruction. Brazil and Bolivia were worst hit. Bolivia saw 9% of its intact forest burned in 2024. The whole region released nearly 800 million tonnes of CO2e, equivalent to a third of the EU27 fossil fuel emissions for the year!

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Dr Tom Harris @drtomharris.bsky.social · 1d

The tipping point temperature for the Amazon rainforest die back is significantly reduced by degradation. This includes deforested patches, roadways, edge effects and burning.

The prolonged 2023-24 drought when combined with human caused fragmentation made it much more susceptible to fire.

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Dr Tom Harris @drtomharris.bsky.social · 1d

Coral reefs have passed their tipping point and new evidence suggests the Amazon will not be far behind. 2024 saw more forest destroyed through wildfires than even deforestation, accelerating the degradation of this vital habitat.

doi.org/10.5194/bg-2...  
#climatechange #tippingpoint #amazon

Extensive fire-driven degradation in 2024 marks worst Amazon forest disturbance in over 2 decades

Abstract. The Amazon rainforest, historically fire-resistant, is experiencing an alarming increase in wildfires due to climate extremes and human activity. The 2023–2024 drought, surpassing previous r...

doi.org

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Dr Tom Harris @drtomharris.bsky.social · 1d

This is a new reality, we must accept the blame and change our ways. There is no acceptable alternative.

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Dr Tom Harris @drtomharris.bsky.social · 1d

We must take this as a wake up call. The Amazon will be next. It’s already suffering hugely. In fact in 2024 there was more destruction caused by wildfires than deforestation. Wildfires are not natural in a wet tropical rainforest.

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Dr Tom Harris @drtomharris.bsky.social · 1d

I was lucky enough to see these miracles of nature back in the 1990’s before the first mass bleaching event. The last time was 20 years ago in the Maldives and things looked bad even then. It’s sobering to think nobody will see those sights ever again.

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Dr Tom Harris @drtomharris.bsky.social · 1d

Widespread dieback is already taking place. Extensive reefs as we know them such as the Great Barrier Reef, the Red Sea, the Indian Ocean and Caribbean Reefs will be lost, although small refuges may survive and must be protected for as long as possible.
phys.org/news/2025-10...

Earth enters 'new reality' as coral reefs reach first climate tipping point

The world faces a "new reality" as we have reached the first of many Earth system tipping points that will cause catastrophic harm unless humanity takes urgent action, according to a report released b...

phys.org

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Dr Tom Harris @drtomharris.bsky.social · 1d

The 2025 Global Tipping Points Report published this week has dire news: Warm-water coral reefs, on which nearly a billion people and a quarter of all marine life depend, are passing their tipping point.
Report: global-tipping-points.org

#climatechange #tippingpoint #coralreef #Amazon #rainforest

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Dr Tom Harris @drtomharris.bsky.social · 2d

This corresponds to 13%, 6.4%, and 19% of the aerosol burden from forest derived isoprene, monoterpenes, and sesquiterpenes, respectively. These results show that diterpenes are an underestimated, but potentially important, source of aerosols, with implications for biosphere-atmosphere interactions.

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Dr Tom Harris @drtomharris.bsky.social · 2d

Since 1900, the world has lost 16% of its forest cover, over half a billion hectares. The contribution of these Diterpenes is estimated as 11.5 million tonnes per year contributing towards 0.63 million tonnes per year to secondary aerosol production.

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Dr Tom Harris @drtomharris.bsky.social · 2d

By cleaning the air of harmful human sulphate aerosol emissions, which kill millions of people a year, we are not just exposing the fossil fuel warming to a greater extent, but also exposing a natural aerosol deficit. Aerosols are vital for forming bright, reflective and longer lasting cloud cover.

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Dr Tom Harris @drtomharris.bsky.social · 2d

This is interesting because, Theodore Rethers and myself hypothesised that some of the recent cloud changes, which are driving down planetary albedo and accelerating warming, may be the result of deforestation on top of human clean air regulations.

drtomharris.substack.com/p/forests-an...

Forests - Another piece of the aerosol puzzle

The reduction of aerosols, both through pollution control and shipping emission rules is unmasking hidden warming, contributing to the current warming acceleration. But what about natural aerosols?

drtomharris.substack.com

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Dr Tom Harris @drtomharris.bsky.social · 2d

A new study has identified unaccounted for aerosol emissions from forest trees. These large volatile organic compounds were not thought to contribute to secondary aerosol formation, but the new study shows a significant contribution.
www.nature.com/articles/s43...
#climatechange #aerosols #forests

Unaccounted impacts of diterpene emissions on atmospheric aerosol loadings - Communications Earth & Environment

Diterpenes are an underestimated source of secondary organic aerosol, accounting for up to 13% of the secondary organic aerosol burden from isoprene, according to combined chamber experiments and chemical transport modelling.

www.nature.com

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Reposted by Dr Tom Harris

Dr Ella Gilbert @drgilbz.bsky.social · 4d

Check out our new pre-print showcasing cutting-edge hi-res regional climate model simulations of Antarctica ❄️

Spoiler alert: they're pretty decent 😎

Link here: egusphere.copernicus.org/preprints/20...

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Dr Tom Harris @drtomharris.bsky.social · 6d

Absolutely. There is no remaining carbon budget for 1.5C, that's gone. I don't think there is much left at all for 2C either. I wrote about it here:
drtomharris.substack.com/p/are-remain...
This new data suggests even less.

Are Remaining Carbon Budgets still relevant?

The latest estimate of the Remaining Carbon Budget says we can emit another 6 years worth of today’s CO2 emissions and stay below +1.5ºC. Given the latest climate data, how can this possible be true?

drtomharris.substack.com

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Dr Tom Harris @drtomharris.bsky.social · 6d

I'm actually preparing an article on AI emissions at the moment, more soon...

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Dr Tom Harris @drtomharris.bsky.social · 6d

Thanks. I'm not actually aware of any issues with Substack. I started using it because other people I respect use it. I've not had any problems.

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Dr Tom Harris @drtomharris.bsky.social · 6d

I understand the concerns around AI, but its emissions in generating graphics is actually small, much smaller than GenAI. That's due to its diffusion approach on small models.
I use it because I don't have a budget for original artwork and don't like to steal from the web. I believe it has impact.

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