Science In Action – "Paris Agreement Impacts and Drought Realities"

BBC World Service | October 16, 2025 | Host: Ronan Pease

Episode Overview

This episode of Science In Action examines the tangible impacts of the 2015 Paris Agreement almost a decade later, focusing particularly on escalating heat and climate change, with a deep dive into research on rising hot days, drought-induced ecosystem changes, and the surprising epidemic controls of ant nests, plus advances in nanotechnology. Experts Freddie Otto, Mindy Smith, and Natalie Strimmet provide insight into how climate pledges are comparing to reality, the vulnerabilities of global grasslands, and how ants naturally manage disease transmission.

Key Themes & Segments

1. The Paris Climate Agreement: A Scorecard (01:54–15:32)

Rising Heat & Missed Targets

• Since the Paris Agreement aimed to cap global warming at 2°C (preferably 1.5°C) above pre-industrial, global temperatures have continued to rise.
• According to Freddie Otto of World Weather Attribution, the world has already slipped past the 1.5°C ambition, with temperatures rising by 0.3°C since 2015.

  "3/10 of a degree of warming really makes a huge difference and we notice it."
  — Freddie Otto [05:04]

Hot Days and Mortality

• "Hot days" are counted as those above the 90th percentile for average temperature, linked to increased mortality (03:53).
  • Nighttime heat is especially deadly for those in poorly insulated homes (04:00–04:39).
  • Just a single five-day moderate heatwave in Europe caused 1,500 excess deaths due to the extra 2°C in some cities.

    "That's just in Europe, because that's the only place where we have the numbers... It is quite sobering."
    — Freddie Otto [09:31]

Geographical Inequality & Adaptation

• Small island nations and countries least responsible for emissions are experiencing the most dramatic increases in hot days, highlighting climate injustice (08:28).
• Societies long adapted to stable climates (India, Sub-Saharan Africa) may suffer even more when pushed outside their historical temperature ranges, impacting agriculture and culture (11:01–12:25).

  "If you push them out of this range... the crops don't grow anymore, the houses don't work anymore, the clothing that people wear... it just does not work anymore."
  — Freddie Otto [11:27]

Successes, Failures, and Legal Power

• The Paris Agreement succeeded in creating a legally binding global framework where every country now tracks and debates emissions. The 2024 ruling by the International Court of Justice further empowered the agreement legally (12:49–15:32).
• Still, most countries prioritize unproven future tech (e.g., carbon capture) instead of proven, systemic changes (e.g., insulating homes, public transit).

  • "We need to do the easy things... we're not doing it. And I think that's the things where we really need to change step."
    — Freddie Otto [15:10]

2. Drought Realities: Grasslands in Peril (15:32–25:19)

Experimental Drought Across Continents

• Grasslands (40% of Earth's land) are now subject to controlled drought experiments on six continents to mimic extreme weather and understand ecological impact (16:25–18:29).
  • "Leaky umbrellas" made of plastic strips reduced rainfall by set percentages, mirroring natural droughts without the added heat (17:42–18:29).

Devastating Multi-Year Impact

• Single drought years cause disproportionate ecological damage, but multi-year droughts (like the Dust Bowl) cause ecosystem collapses (19:00–21:00).

  • Roots and soil microbial life are decimated, affecting regrowth and future productivity.

    "This is just not even plant growth that we see, these profound impacts. They occur below ground where we don't see them."
    — Mindy Smith [22:00]

• Post-drought, exotic non-palatable plants (e.g., Russian thistle) overtake former forage grasslands, even if green returns above ground.

  • "While you could say it recovered, it actually didn’t. Because what we saw was the collapse of the main forage grasses that the cattle depend upon and they're still not recovered four years later."
    — Mindy Smith [23:03]

Irreversible Shifts

• Loss of root structures and key species threatens farm livelihoods and biodiversity long-term; parallels drawn directly to Dust Bowl history (21:52–25:19).

3. Nanotechnology: The Unusual Promise of Ultra-Thin Water (27:33–34:00)

Confined Water’s Surprising Properties

• Water squeezed into nanoscopic spaces between graphene-like materials takes on radically new behavior—conducting electricity much more than expected (28:39–31:46).

  • "One would expect essentially [pure water] doesn't conduct. And instead we found it conducts really a lot, as high as superionic materials."
    — Laura Fumigale [30:41]

• This insight could lead to next-gen electronics, batteries, or even new types of biological studies, as ultra-thin water layers mimic cell interiors (32:00–32:59).

Potential for Tech & Bio-Mimicry

• The Manchester team is actively investigating devices combining such water layers and 2D materials like graphene for nanochips (33:10–33:51).

4. Epidemic Controls in Ant Nests: Architectural Immunity (34:00–42:13)

CT Scans for Ant Nests

• Using micro-CT, Bristol researchers visualized the complex inner structure of ant nests, which change in response to disease threats (34:44–36:39).

Behavioral Adaptation

• Exposed ants self-isolate by spending more time outside the nest, voluntarily taking on riskier jobs to protect the colony (37:36–38:28).

  • "The ants that have been exposed to the infectious pathogen exclude themselves voluntarily from the colony, so they spend more time on the outside to reduce the risk of contamination."
    — Natalie Strimmet [38:13]

Modular Nest Design Reduces Disease Spread

• Nests built under disease threat feature more “modularity”—compartmentalized chambers and tunnels—slowing disease transmission (38:51–39:37).

  • "If you have a compartmented group, disease transfers less well than if everyone interacts homogeneously. And here when we look at the ants, we saw the same thing."
    — Natalie Strimmet [40:08]

Instinctive Collective Action

• Unlike humans needing instructions, ants have evolved to instinctively restructure collective behavior and architecture for the colony’s safety—even sacrificing personal interests when required (40:42–42:13).

  • "They've had millions of years of evolution... there's less conflict between individuals... all workers in the colony want the queen to do well."
    — Natalie Strimmet [41:07]

Notable Quotes & Moments

• On climate injustice:

  "The strongest increase in these hot days we see... is in countries that have really done the least to cause the problem."
  — Freddie Otto [08:28]

• On climate change legacy:

  "It's those below ground impacts that we think are going to be those legacies that prevent recovery in the future after these kinds of droughts."
  — Mindy Smith [22:00]

• On Paris Agreement’s importance:

  "We should really not underestimate how much of an achievement it is to have a global, legally binding framework..."
  — Freddie Otto [12:49]

• On ant society vs. humanity:

  "We can't request individuals to sacrifice themselves for the group. That would be unethical. But the ants do that."
  — Natalie Strimmet [41:30]

Timestamps for Major Segments

• Paris Agreement impacts & climate realities: 01:54–15:32
• Grasslands & drought legacies: 15:32–25:19
• Nanotechnology with atom-thick water: 27:33–34:00
• Ants & architectural immunity: 34:00–42:13

Summary Conclusion

This episode clearly demonstrates the gulf between climate promises and lived reality—global warming’s pace is accelerating, vulnerable regions suffer the greatest, and adaptation is essential but yet incomplete. Field experiments reveal that repeated drought leaves lasting scars on vital grasslands, while ants show how coevolved behaviors and group architecture can help limit epidemics, offering inspiration for human society. Meanwhile, cutting-edge nanotech may one day mimic or even harness nature’s most fundamental elements. Science In Action deftly weaves these stories, underscoring the urgency, complexity, and wonder at the frontiers of science and adaptation.