Abstract:
Halting global warming requires achieving climate neutrality, i.e., a balance between greenhouse gas sources and sinks. My presentation focuses on integrated assessment models (IAMs), modeling tools to assess pathways to climate-neutral economies and energy systems, and insights derived from them. Key elements for achieving climate neutrality are (i) rapid and deep decarbonization of power supply, (ii) electrification of most end-uses, (iii) transition to biomass and renewable hydrogen-based fuels for residual non-electric energy demands, and (iv) carbon dioxide removal. With comprehensive climate action warming can still be held well below 2°C and returned to below 1.5°C.
Bio:
Gunnar Luderer leads the Energy Transition Lab at PIK, and is the Lead Scientist for the REMIND Integrated Energy Economy Climate Model, and serves as Deputy Chair of Research Department 3 - Transformation Pathways. He is also Professor of Global Energy Systems Analysis at the Technical University of Berlin. He contributed to several several reports of the Intergovernmental Panel on Climate Change (IPCC), as well as UNEP Emissions Gap Reports. He studied Physics, Economics and Atmospheric Sciences at the University of Heidelberg and Oregon State University. He performed his doctoral studies at the MPI for Chemistry in Mainz. Gunnar Luderer has published more than 100 papers in peer-reviewed scientific journals, and is regularly recognized as one of the World's most Highly Cited Researchers by the Web of Science Group.
Summary:
Focus: Energy transitions towards climate neutrality
Climate change:
2024: first year above 1.5C
2015-2024: 10 warmest years on record (probably going back 100,000 years)
Warming has been extremely rapid compared to prior changes (e.g. ice age transitions)
We’re getting close to key tipping points
Death of coral reefs
Melting of ice sheets (Arctic, Greenland, Antarctica)
Impact on economic prosperity
Warming can impact economic growth relative to no-warming baseline
~20% from 1.5-2C warming
~60% from 3-6C warming
Economic damage from 1 Ton CO2 ~ $200 (US EPA, 2023)
In contrast, the cost of decarbonizing the economy is a few % of growth
Every Ton CO2 adds to global warming: total warming roughly proportional to cumulative emissions
Implication: if we want to limit warming to a specific temperature there is a total budget for CO2 emissions
Integrated Assessment Modeling of Climate Change: REMIND: https://www.pik-potsdam.de/en/institute/departments/transformation-pathways/models/remind
Macroeconomic model:
Maximize welfare
Subset to budget constraints
And production function
Energy system (process-detailed)
Energy supply
Buildings
Industry&materials
Transport
CO2 removal and use
External models:
Climate change: MAGICC: https://magicc.org
Damages & economic losses
Environmental impacts (premise LCA)
Agriculture and Land-use (MAgPIE: https://www.pik-potsdam.de/en/institute/departments/activities/land-use-modelling/magpie)
12 world regions
Time horizon: 2005-2100
Co2, CH4, N2) and fluorinated gases
Key non-linearitiers: tech learning, renewable integration, production function
Can simulate various scenarios for decarbonizing the world
Broken down by industry-specific reductions
Easier to decarbonize: power supply
Harder: transportation, steel making
Require carbon removal tech to make up for the hard to decarbonize sectors and undo past damage
Energy technology trends
Solar and wind have gotten significantly cheaper
Now generally cheaper than non-renewables
Batteries have dropped in costs by 80-90%
Threshold $150/KWH of where electric cars become cheaper than gas based on total cost of ownership
However, nuclear power is not getting cheaper, so most likely careful combination of solar, wind, batteries and long-term storage via H2 will be the most cost-effective option
Can evaluate the impacts of different climate policies and tech trends
Emissions reductions
Energy prices for different types of fuel and power generation types
Electricity share of global demand
Buildings and industry can be driven by electricity
Transport:
Easy to electrify road transport
Oceanic shipping and planes require high energy density, so liquid fuels will predominate, hopefully created using clean power
Steel manufacture will take time to decarbonize
Buildings: expect increase in power demand for heating/cooling, cooking and data centers but this demand can be electrified
Competition between direct and indirect electrification (slide 30)
Direct electrification significantly cheaper than e-fuels: building heating, light transport
Direct electrification and e-fuels similar costs: high temp heat, heavy duty trucks
Impossible-toelectrify sectors: aviation, shipping, chemical feedstocks, primary steel
Indirect electrification: e.g. power-to-gas e-fuel
Lower efficiency: <.5 MWH_thermal / MWH_electric
Direct electrification : e.g. heat pump
Higher efficiency: 3 MWH_thermal / MWH_electric
Near-term climate policy implications
Based on current policies we expect a stabilization of emissions but no decline
To limit warming we need drastic declines
Gap:
20GTons/year in 2030
25-30Gtons/year in 2035
For scale: we can scale up reforestation but its still not enough and climate change is making reforestation less effective
Must up-scale current tech quickly
Renewable energy (solar, wind)
Current pipeline of projects is looking good
Electric cars:
Need 60-80% market share by 2030 for 1.5C
On-track in some markets (Norway, China) but not yet in most of the world
Carbon capture and storage from current emission sources
Currently 50 MT CO2/Year in 2022
Need 100x by 2050
Hydrogen electrolysis: need 400x by 2030
Direct air capture: need 100,000x increase by 2050
Expected cost of decarbonization transition: several $Trillion/year, mostly from private investment