This is the 8th lecture in our course on the philosophy of climate change. Here we look at how we gain knowledge about the climate system. We examine climate data and climate models, as well as the uses of these methods and tools.

1. 8. Climate Science as
Methods and Tools
UNT Phil 4250 Climate Change
Adam Briggle (he/him/his)
adam.Briggle@unt.edu

2. Ackbar reads
the news

3. Outline
• Science in General
• Method: Science as “epistemically special”
• Tools: Quantification (temperature – lived and measured)
• Two Approaches to Climate Science
• Climate data
• Climate modeling
• Three Uses of Climate Science Methods and Tools
• Detection
• Attribution
• Projections

4. The methods of science
• Appeal to nature (physis and logos) in a
non-narrative rationality
• Standards for testing/verifying/falsifying
claims
• Proof-in-the pudding: predictions and
technologies that function
• Implication: Epistemically special
(privileged access to truth/reality) and
privileged in decision-making.

5. Scientific Tools
“Man is the measure of all
things” “The same wind blows
hot or cold…”
Tools allow quantification and
measurement in ‘objective’
ways: temp, precip, pressure,
GHG concs, time…
Thermometer based on energy
as a universal currency,
convertible, and measurable
with standard units.

6. How would
you study the
climate?

7. Two Approaches to Climate Science

8. Climate Data 1
• Station-based data sets

9. Climate Data 2
Reanalyses

10. Climate Data 3
• Paleoclimate Reconstructions
• Use proxies:
• Ice cores
• Tree rings
• Fossils
• Lake sediments
• More

11. Climate
Modeling
“Climate models use equations to
represent the processes and
interactions that drive the Earth’s
climate…The models are based on
the same laws and equations that
underpin scientists’ understanding
of the…Earth system.”
https://www.carbonbrief.org/qa-how-do-climate-
models-work

12. https://www.carbonbrief.org/qa-how-do-climate-models-work

14. Types of Models
• GCMs: Global Circulation or Global Climate (atmosphere, ocean, heat
balance)
• ESMs: Earth System – GCMs ‘pimped’ to include vegetation,
biogeochemical cycles, and more
• IAMs: Integrated Assessment – account for social factors (economics,
GHG emissions, policies, development, etc.)
• (Also RCMs: Regional Climate Models)

15. Model Inputs and Outputs
• Inputs:
• Forcings: especially GHG “emissions scenarios”
• Most models use one or several RCPs (Representative Concentration Pathways) –
plausible descriptions of the future based on socio-economic scenarios.
• Outputs:
• A picture of what the climate system will look like, with different kinds and amounts of
variables (e.g., temps, precipitation, wind speeds, etc.) on varying scales of resolution.
• Climate sensitivity – estimates about how sensitive Earth is to increases in GHG
concentrations.
• How well have they done?
https://www.instagram.com/p/BZ38rf7F3al/?utm_source=ig_embed&utm_campaign=embed_video_watch_again

16. Three Uses of Climate Methods and Tools
• Detection: Did the climate change?
• “the process of demonstrating that climate or a system affected by climate has
changed in some defined statistical sense, without providing a reason for that
change.” (IPCC-glossary: 1452)
• Attribution: What caused the observed change?
• Extreme event attribution as a growing field…not so much ‘cause’ as ‘increase
likelihood’ or ‘increase severity’
• (The “consensus position” – it is “virtually certain” that mean surface temps.
have increased since 1950 and it is “extremely likely” that more than half of
this increase is due to anthropogenic GHG emissions).
• Projections: If we do X, what will the future look like?

17. Summary
• Climate science is multi-method, multi-tools, multi-disciplinary
• It uses theories and natural laws, observations, and models to
understand, explain, and predict the climate.
• Growing bodies of research bolster both a broad consensus and
ongoing debates/uncertainties.
• We should wonder… do we need more and more science? Is
knowledge the end in itself or a means to action? What kind of
research is relevant and needed now?

18. “If you feel like
you know less
now than you did
before, that’s
probably a
success!”
-- Admiral
Ackbar