A tool for building climate pathways

Every country has a path to net zero. Build yours.

Pathways Explorer is a free tool, built on an open-source model, used by ministries, cities, and NGOs to design credible decarbonisation scenarios, sector by sector, country by country. Pick yours on the map, or start from a regional preset.

Bubble · latest emissions (MtCO₂e)

Colour · 2050 reduction · REF (vs 1990)

<45%

45-55%

55-65%

≥65%

Search a country…

Selected

… · reference pathway

Total GHG emissions: N/A
Emissions evolution: N/A
2050 reduction · REF (vs 1990): N/A

Pre-loaded with the historical inventory, sectoral levers, and a published reference pathway. Free with an account.

Used byEuropean Commission·Belgian government·European Climate Foundation·ClimateWorks Foundation·CAN-Europe

§ 01 · How it works

From first click to a credible scenario, in a single session.

Nothing to install: sign in once and start exploring. The model runs on Climact servers, the results appear in your browser. Every lever comes with a calibrated baseline and documented sources: you move the levers, the numbers update.

Pick a country

Or a region. The historical inventory and reference pathway load automatically.

Set ambition per sector

Six sectors, each with a 1 to 4 ambition lever. Start from the baseline or a published plan.

Buildings

Transport

Industry

Read the result

Emission curve, energy mix, investment cost. Compared automatically to official targets.

Share or export

Save your scenario behind your account, then download the data as CSV or share it with a permalink.

↗Permalink to your scenario

⬇CSV data · PNG charts

§ 02 · What's inside a pathway

Six sectors, one horizon: every number traceable.

A pathway is the sum of six sectoral trajectories. Below: the reference scenario for …, drawn from the same model that powers the workspace.

… · reference pathway

Emission pathways, 2000-2050 (MtCO₂e)

Loading reference scenario…

Illustrative shape · run yarn workspace @climact/patex snapshot:landing to populate real numbers.

§ 03 · Use cases

A shared workbench for net zero pathways.

Climate commitments land. Implementation is harder. The tool is designed to support the people actually doing the work: policy teams, consultants, city networks, with a shared, reproducible way to test scenarios.

Co-create and challenge pathways

Build new net zero pathways with your partners, or put existing ones to the test, on robust and transparent data.

→ Every lever and source documented

Plan the implementation

Quantify the energy and material demand of a pathway and identify the levers to activate first to accelerate the transition.

→ Energy in the tool, materials on request

Explore the co-benefits

See what your pathway means for the economy, public health and the wider environment.

→ Co-benefits module on request

§ 04 · Open source

The model is open.

patex is the Python package behind the Pathways Explorer: about 240 levers, sector by sector, year by year up to 2050 or 2100. Its source code is public and every module is documented, from its inputs to its equations. Researchers, civil servants and NGOs can run the model, audit it, or extend it.

Packagepatex · Python 3.11

LicenseAGPL-3.0-or-later

Documentationpatex.readthedocs.io

Repositorybitbucket.org/climact/patex

DataSynthetic example dataset in the repository. The full datasets are built by Climact: contact us for access.

Read the docs Source code on Bitbucket

1 · In your browserNothing to install, full Climact datasets

# Open the explorer and build a scenario

→ pathwaysexplorer.climact.com

2 · Run the model locallyCommand line, synthetic dataset shipped in the repo

# Clone the repository and install it with uv

$ git clone https://bitbucket.org/climact/patex.git

$ cd patex && uv sync

# Run region XX with every lever at level 2

$ uv run patex run XX --dataset examples/data/synthetic --levers-default 2 -o xx.pkl

3 · Use it from PythonSet the levers, run, read the results

from patex import model

from patex.core.context import RunContext

from patex.core.dataset import Dataset

DATASET = 'examples/data/synthetic'

# levers = {lever code: level 1 to 4}, every lever of the dataset

data = Dataset(DATASET, country_filter='XX', levers=levers)

ctx = RunContext(country_filter='XX', levers=levers, data=data)

results = model.run(ctx)

§ 05 · Access options

Free for the public good, premium tools for those who need depth.

You sign in once so we can keep the platform free, prioritise support, and understand who's using it. Free covers the whole model on your own; Pro adds the Climact team; Pro Advanced adds connected modules.

Free

The whole model, on your own.

Build and save scenarios for every available country
Compare with reference and official pathways
Detailed sectoral assumptions and sources
Export data (CSV) and charts (PNG), share scenario links

Pro

Build your scenarios with the Climact team.

Onboarding and training for your team
Expert support to design and review new scenarios
New countries and regions not yet in the tool
Custom regional hierarchies

Pro Advanced

Advanced features and connected modules.

Split ETS and indirect emissions
Energy system implications with PyPSA
Co-benefits of your pathways with MICAT
Material demand with Climact experts

§ 06 · Beyond the Pathways Explorer

The Pathways Explorer is one tool. The decarbonisation challenge needs many.

The Pathways Explorer is part of a broader Climact ecosystem: city-scale calculators, an EU ETS simulator, energy-system explorers, corporate climate intelligence and client portals. Reuse the data, go deeper with another tool, or talk to us about what's missing.

EU City CalculatorCities

Free, open-source web tool to simulate and compare climate neutrality scenarios at city scale, same modelling spirit as the Pathways Explorer.

Discover →

ETS SimulatorCarbon markets

A transparent, fully parameterised model of the EU Emissions Trading System: you set the policy, the engine projects the whole market to 2040.

Discover →

PyPSA-EUR Results ExplorerEnergy systems

Browse hourly and annual outputs of PyPSA-EUR energy-system runs by country and carrier, a deep-dive complement to Pathways Explorer scenarios.

Discover →

SiriusCorporate

Climate intelligence platform for investors and corporates: physical, transition and biodiversity risk at site and portfolio level.

Discover →

myClimactPortal

Climact client portal: projects, deliverables and shared workspaces, including the full tool catalogue.

Discover →

Something missing?

Tell us what you need. New tools and modules are added as the climate questions evolve.

Talk to Climact →

Your country's pathway, in the open.

Free account · results in your browser

The model is open.

Packagepatex · Python 3.11

LicenseAGPL-3.0-or-later

Documentationpatex.readthedocs.io

Repositorybitbucket.org/climact/patex

DataSynthetic example dataset in the repository. The full datasets are built by Climact: contact us for access.