LAYER 1: PLANETARY FOUNDATIONS
Climate System
The two interconnected boundaries driven by atmospheric CO2 – Climate Change and Ocean Acidification.
In 30 Seconds
Two planetary boundaries share the same driver – atmospheric CO2:
- Climate Change– Atmospheric CO2 and radiative forcing (the “warming” boundary)
- Ocean Acidification– CO2 absorption by oceans (the “other CO2 problem”)
Climate Change is already crossed (since ~1988). Ocean Acidification is approaching but not yet breached. Both will continue to worsen until we achieve net-zero emissions – making decarbonisation the defining business transformation of our era.
Where This Fits
This page covers two of the nine planetary boundaries – the “climate-related” boundaries that together govern Earth's energy balance and ocean chemistry.
The Nine Boundaries – Climate Cluster
CLIMATE-RELATED (This Page)
- Climate Change
- Ocean Acidification
OTHER BOUNDARIES
- Biosphere Integrity
- Land-System Change
- Freshwater Change
- Biogeochemical Flows
- Novel Entities
- Stratospheric Ozone
- Atmospheric Aerosols
These two boundaries share a common driver: atmospheric CO2. Every tonne of CO2 emitted both warms the atmosphere and acidifies the oceans. This is why decarbonisation addresses both boundaries simultaneously.
The Two Interconnected Boundaries
Climate Change has been crossed for decades. Ocean Acidification is approaching its limit. Both are driven by anthropogenic CO2 emissions.
1. Climate Change
CROSSEDAtmospheric CO2 concentration and radiative forcing – the fundamental driver of global warming
What It Measures
- CO2 concentration: Parts per million (ppm) of CO2 in atmosphere
- Radiative forcing: Energy imbalance (W/m²) driving warming
- Global temperature: Deviation from pre-industrial baseline
Current Status
- CO2: ~425 ppm (boundary: 350 ppm) – 21% over
- Radiative forcing: ~2.9 W/m² (boundary: 1.0 W/m²)
- Temperature: +1.2°C above pre-industrial (2024)
- Crossed since approximately 1988
The Paris Agreement Context
The 1.5°C and 2°C targets from Paris correspond to different levels of boundary transgression. At 1.5°C, we remain in a “zone of increasing risk.” Beyond 2°C, we enter “high risk” territory with potential tipping points: ice sheet collapse, permafrost methane release, Amazon dieback. Current policies trajectory: 2.5–2.9°C by 2100.
Business Relevance
Climate change creates both physical risks (extreme weather, sea level rise, supply chain disruption) and transition risks (policy changes, technology shifts, market repricing). Every company faces decarbonisation pressure through regulation (CSRD, SEC), investor expectations (TCFD/ISSB), customer demands, and competitive positioning. Science-based targets (SBTi) now cover companies representing >35% of global market cap.
2. Ocean Acidification
APPROACHINGCO2 absorption by oceans – the “other CO2 problem” that threatens marine ecosystems
What It Measures
- Aragonite saturation: Availability of calcium carbonate for shell-building organisms
- Ocean pH: Acidity level (lower = more acidic)
- Carbonate chemistry: Balance of dissolved carbon species
Current Status
- Aragonite saturation: ~84% of pre-industrial (boundary: ≥80%)
- pH decline: -0.1 units since 1800 (30% more acidic)
- CO2 absorption: Oceans absorb ~25% of anthropogenic emissions
- Approaching but not yet crossed
Why It Matters
Ocean acidification threatens calcifying organisms: corals, shellfish, plankton. These form the base of marine food webs. Coral reefs support 25% of marine species and protect coastlines worth trillions. Unlike warming, which can theoretically be reversed with cooling, ocean chemistry changes persist for thousands of years. This is an irreversibility issue.
Business Relevance
Direct exposure for fisheries and aquaculture (shellfish industry particularly vulnerable),coastal tourism (reef degradation), and coastal property (reduced storm protection). Indirect exposure through marine ecosystem degradation affecting global protein supply. Often overlooked in corporate climate strategies focused solely on temperature.
Why These Boundaries Are Interconnected
Both boundaries are driven by the same root cause: anthropogenic CO2 emissions.
The Carbon Pathway
~40 Gt
Annual CO2 emissions
~45%
Stays in atmosphere
(Climate Change)
~25%
Absorbed by oceans
(Acidification)
(Remaining ~30% absorbed by land ecosystems)
Shared Driver
Every tonne of CO2 emitted contributes to both warming (atmosphere) and acidification (ocean). Decarbonisation is the solution to both.
Compounding Effects
Warmer oceans absorb less CO2 (more stays in atmosphere), but absorbed CO2 acidifies faster in warmer water. Climate change accelerates acidification.
Different Timescales
Atmospheric warming could theoretically be reversed through cooling. Ocean chemistry changes persist for millennia. Acidification is less reversible.
Feedback Loops
Ocean acidification weakens marine carbon sinks (coral, shellfish, plankton), reducing future CO2 absorption capacity, accelerating atmospheric accumulation.
The Implication
There is no pathway to solving either boundary without addressing CO2 emissions at source. Adaptation is necessary but insufficient. Mitigation – rapid, deep decarbonisation – is the only response that addresses root cause. This is why net-zero commitments and science-based targets have become the central organising framework for corporate climate action.
How This Maps to Practitioner Categories
Professional bodies like ISEP use “Climate Change Mitigation & Adaptation” as a practice area. This page explains the planetary science that practice area addresses.
ISEP: Climate Change Mitigation & Adaptation
This practice area spans multiple layers of our framework:
| Layer | Climate Content |
|---|---|
| L1: Planetary Foundations | Climate Change + Ocean Acidification boundaries (this page) |
| L4: Policy & Governance | UNFCCC, Paris Agreement, NDCs, carbon pricing, CBAM |
| L5: Corporate Action | GHG accounting, SBTi, TCFD/ISSB, transition planning |
| Capital Flows | Carbon markets, green bonds, climate finance |
The Pandion Perspective
Climate practitioners often focus on emissions accounting and target-setting (L5) or policy engagement (L4). Understanding the underlying planetary science (L1) provides context for why certain thresholds matter and what's at stake if they're breached. It's the difference between compliance and strategic conviction.
Business Risks & Opportunities
Physical Risks
Direct impacts from changing climate
- Acute: Extreme weather events, flooding, wildfires, storms
- Chronic: Sea level rise, water scarcity, temperature shifts
- Supply chain: Agricultural disruption, infrastructure damage
- Operations: Cooling costs, water availability, asset stranding
- Insurance: Rising premiums, coverage withdrawal in high-risk areas
Transition Risks
Impacts from shifting to low-carbon economy
- Policy: Carbon pricing, CBAM, mandatory disclosure, phase-outs
- Technology: Stranded assets, obsolete processes, new competitors
- Market: Shifting customer preferences, green premiums
- Reputation: Greenwashing accusations, activist pressure, talent flight
- Legal: Climate litigation, fiduciary duty claims
Scope 1
Direct emissions from owned/controlled sources
Fuel combustion, fleet, industrial processes
Scope 2
Indirect emissions from purchased energy
Electricity, heating, cooling, steam
Scope 3
All other indirect emissions (value chain)
Supply chain, product use, investments
The Opportunity Frame
Climate transition creates massive market opportunities: renewable energy, efficiency technology, low-carbon products, carbon removal, climate adaptation services. Companies leading the transition capture market share, attract talent, and reduce long-term risk exposure. The first-mover advantage in decarbonisation is significant and time-limited. Companies setting science-based targets now are positioning for the economy of 2030–2050.
Who Works on Climate Systems
Science & Research
Understanding the climate system
IPCC, WMO, NOAA, Met Office, universities, research institutes
What is happening and what will happen?
International Governance
Global coordination and agreements
UNFCCC, COP process, Paris Agreement, IPCC Working Groups
What should the world do collectively?
Standards & Frameworks
Translating science to action
SBTi, GHG Protocol, CDP, TCFD/ISSB, ISO 14064
How should organisations measure and commit?
Carbon Markets
Pricing and trading mechanisms
EU ETS, Verra, Gold Standard, ACR, CAR, national schemes
How do we price emissions and fund mitigation?
Technology & Solutions
Mitigation and adaptation
Renewables, efficiency, electrification, CCUS, adaptation tech
What technologies enable decarbonisation?
Finance & Investment
Mobilising capital for transition
Climate funds, green bonds, transition finance, GFANZ members
How do we fund the net-zero transition?
The Pandion View
Climate change is the most recognized planetary boundary because its impacts are already visible and its solutions – decarbonisation – drive the largest economic transformation in history.
But climate is not the whole story. Ocean acidification shows that even if we solved warming, CO2 emissions would still degrade marine ecosystems. And climate solutions that ignore other boundaries – like biofuels driving deforestation – can make the overall situation worse. Systemic thinking matters.
We help clients understand climate in context: the science that defines boundaries, the policy that translates them into requirements, and the business transformation needed to respond. See also Biosphere & Living Systems – the life-related boundaries that climate change increasingly threatens.
Where To Go Next
Targets & Commitments (L5)
Science-based targets, net-zero commitments, and how to set credible decarbonisation pathways.
Carbon Markets
How carbon pricing, compliance markets, and voluntary credits work – and their role in climate finance.
Biosphere & Living Systems
The four life-related boundaries – what climate change increasingly threatens.
All Planetary Boundaries
The complete L1 overview – all nine boundaries and why they matter for business.
Sources: Stockholm Resilience Centre (Planetary Boundaries 2023 update), IPCC AR6, Global Carbon Project, NOAA, SBTi, ISEP Policy & Practice Areas. This content is for educational purposes. For specific guidance, consult appropriately qualified professionals.