Inside the post-pandemic power sector’s emissions ups and downs

Electricity generation annual emissions for G20 countries graph

This story is already familiar to most, and for many, already feels like a distant memory: in March 2020, much of the world went into lockdown as COVID-19 raged. Everyday life paused and economic activity slowed. In tandem, air pollution and carbon emissions both dropped noticeably.

But then, as life resumed and the global economy returned closer to normal in 2021 and 2022, emissions predictably rebounded. This was true across more or less every sector of the economy, including power sector emissions. The United States — the world’s #2 source of carbon emissions, both overall and for electricity generation in particular — is a good example of this general trend. So is the United Kingdom.

Here at WattTime, we dug deeper into G20 countries’ pre-, during-, and post-pandemic electricity emissions — all cataloged in the detailed Climate TRACE data — and found some interesting alternate trends that deviated from the “standard” pandemic emissions trajectories seen in the U.S. and other countries.

They largely fell into three buckets: 1) countries whose power sector emissions climbed straight through the pandemic and have continued rising, 2) countries whose emissions fell but didn’t rebound, and which have continued falling, and 3) countries whose electricity emissions underwent sharp booms and busts. Why these trends happened in any given country is especially interesting.

Countries where electricity emissions climbed straight throughout the pandemic — and beyond

electricity emissions increase for China and India during pandemic

Across the 19 individual countries of the G20 (the G20 currently also includes the European Union and African Union), most saw their power sector emissions slump during the 2020 pandemic and about half of the G20 hit all-time lows that year. But for a select few, emissions from their country’s electricity generation didn’t blink. It rose during the pandemic and has continued climbing higher since.

China’s power sector emissions march upward: China is the world’s #1 source of greenhouse gas pollution, and the power sector is the country’s single largest source of carbon emissions, according to Climate TRACE data. Those emissions rose in 2020 vs. 2019, then again in 2021 and yet again in 2022 to a new all-time high. Despite rapidly expanding clean energy generation (China installed about as much new solar in 2022 as the rest of the world combined), ongoing expansion of the country’s coal-fired generation and a drought that impacted its sizable hydro fleet have resulted in power sector emissions still creeping upward.

India’s emissions ascent continues: Although India’s rising power sector emissions briefly stalled during the pandemic, they’ve since reached an all-time high in 2022. In fact, India is one of only three countries (behind China and the United States) whose annual emissions from electricity generation exceed 1 billion tonnes — and India’s electricity emissions at #3 globally equals countries 4, 5, and 6 combined. Coal-fired generation comprises more than 70% of the nation’s power mix. Ironically, summer heat waves intensifying from climate change prompted the country’s leaders to mandate that coal-fired generation operate at full capacity to meet surging electricity demand, further contributing to the climate-induced problem. Early this year, India announced plans to further expand its coal-fired capacity.

Countries where power sector emissions have stayed on the down slope

Australia, Japan, and South Africa emissions declined during and after the pandemic

Emissions in the Land Down Under keep declining: In sunny Australia, power sector emissions have been on a five-year run of annual declines since at least 2017. They fell 3.8% during the 2020 pandemic year vs. 2019, then 5.1% in 2021 and a further 4.1% in 2022, totaling an 18.7% drop from 2017 levels. Large declines in the country’s coal-fired generation — and, in parallel, a meteoric rise of new solar capacity, plus some new wind — have driven down overall electricity emissions. These trends are expected to continue, with AEMO forecasting that coal could all but disappear from the nation’s generation mix within a decade.

Falling emissions in the Land of the Rising Sun: As many will recall, Japan largely relied on nuclear power until the 2011 earthquake and subsequent Fukushima accident. In response, the country shuttered its nuclear reactors and pivoted to fossil-fueled generation, including hefty LNG imports, raising the nation’s power sector emissions in the short term. But those emissions have been declining since at least 2015, reaching lows in 2021 not seen since before the Fukushima incident. In 2022, Japan’s power sector emissions bumped up slightly, driven by increased coal-fired generation as a reaction against higher natural gas prices. However, growing renewable generation and offshore wind ambition are keeping the country on an overall downward emissions trajectory.

Coal-dependent South Africa turns the corner: Thanks to coal’s 85% dominance of South Africa’s electricity generation mix, the nation boasts the highest power sector carbon intensity of any country in the G20. There are signs that the situation may now be changing, as evidenced by sharp declines in the country’s electricity emissions in 2022. In recent years new solar installs have been booming, reports BNEF, while state-owned utility Eskom grapples with an ongoing energy crisis and charts a pathway that decommissions much of the nation’s coal-fired power plants as part of a just energy transition plan.

Countries on an electricity emissions roller coaster

Brazil and Mexico emissions have been variable

Drought hurts hydro in Brazil: Hydro comprises nearly two-thirds of Brazil’s electricity generation. It’s one big, wet reason why the country ranks 6th overall globally for GHG emissions, yet sits outside the top 30 for electricity generation emissions in particular. Consequently, Brazil has one of the cleanest power sectors of any major economy. But across the years 2020–2022, a curious thing happened amidst the nation’s power sector emissions. They predictably slumped during the 2020 pandemic, then skyrocketed 68.8% higher in 2021, before falling massively to all-time lows in 2022. Why? As it turns out, in 2021 drought hit the country hard, suppressing hydro generation and prompting elevated LNG imports to compensate. By 2022, the rains returned while wind and solar expanded.

Mexican manufacturing and the growth of natural gas generation: After years of declining power sector emissions — through the pandemic and into 2021 — Mexico’s electricity emissions rebounded massively in 2022, to near an all-time high. At least three concurrent factors contributed: 1) a rise in Mexico’s manufacturing sector (partly in response to nearshoring trends), 2) drought that reduced the country’s hydro generation to a 20-year low, and 3) a significant bump in natural gas-fired electricity generation. Meanwhile, the nation’s lawmakers eliminated its Climate Change Fund and have put the future of clean energy development into question.


Looking back across these examples, it becomes clear that specific causes in each country’s power sector are driving the macro trends for annual electricity emissions: 1) Where wind and solar are scaling and capturing a great portion of a nation’s generation mix, fossil-fueled electricity emissions are falling. 2) In countries where the buildout of coal-fired generating capacity continues, electricity emissions are still rising, too. 3) For countries with a notable slice of hydro power in their electricity mix, they are backfilling drought-reduced hydro generation with natural gas, causing electricity emissions to yo-yo.

Later this year, WattTime and Climate TRACE will update our data with 2023 numbers, too. It will be interesting to see how these and other countries continue to track.

The Visionary Leaders Backing the Builders of AI for Humanity

Announcing New API, New Regions, New Data Signals

As WattTime continues to ‘bend the curve’ of emissions reductions, we’re excited to announce the release of our upgraded API (version 3 or v3), which includes new regions and data signals in addition to a more refined and intuitive schema. By expanding to new countries and regions, we’re enabling our partners to bring emissions-reducing technology to a greater global audience. With additional grid signals, we’re able to maximize human health benefits in addition to greenhouse gas (GHG) reductions.  


The v3 API brings many improvements, including more intuitive and descriptive data delivery, error handling, and more. We don't undertake changes to our API lightly. We think the upgrades we've made in API v3 will be well worth the effort, as they will unlock greater opportunities for emissions reductions. We're here to support our partners as they begin using the new API.

New Countries and Regions

We have also released data for 12 new countries, which will only be available in API v3: 

  1. Mexico
  2. Japan (10 regions)
  3. South Korea
  4. Brazil
  5. India
  6. Chile
  7. Peru
  8. Turkey
  9. Malaysia
  10. Nicaragua
  11. Philippines
  12. Singapore

Check out our coverage map to see our full coverage, now with unique map layers for each data signal we offer through the API.

New Data Signals

In addition to CO2, the new API now offers our health damage data signal, which estimates the damage to human life and health caused by emissions from electricity generation based on the time and place that electricity is used. While currently only available in the US, this signal can be used to make decisions that reduce negative impacts on human life and health. IoT and EV companies have already begun using it as an input signal to device scheduling optimization, or to create a UI element advising users when to run appliances or plug in an EV. It can be used in tandem with the marginal operating emissions rate (MOER) to co-optimize device operation to reduce GHG emissions and damage to human health.

We’ve also added an average operating emissions rate (AOER), which is the average emissions rate (in lbs of CO2 per MWh) of all the generators operating at a particular time, weighted by their energy output. Using this signal for load shifting wouldn’t reduce emissions, but many companies find the data helpful for calculating total annual footprint for GHGP Corporate Standard, Scope 2.

To learn more about the different signals we provide, visit our data signals page.

Refined Handling of Real-time and Historical Data

Two of the biggest changes between our v2 and v3 API are our handling of real-time and historical data. 

“Real-time” data (formerly found in both the /v2/data and /v2/index endpoints), used to vary in recency, typically from five minutes old up to six hours. Now, all real-time data is always available within five minutes (in the /v3/forecast endpoint, the first data point applies to the current five-minute period). This provides a single, more reliable place to look for the data that apply to right now.

“Historical” data (formerly found in both the /v2/data and /v2/historical endpoints) used to be created typically within five minutes to six hours, but was never changed or updated after that. Now we’ve designed v3 such that we can still deliver historical data within a few hours (in the /v3/historical endpoint), but we can update those data later if more or better source data for a particular data point become available (data points are not overwritten, but additional points for the same timestamp become available). This allows us to maintain a historical database of emissions data that is more representative of the best available source information.

Transition Resources

We want this transition to be as easy as possible and worth the effort to upgrade. We’ve prepared a number of resources to guide our partners through the transition and help with getting acquainted with the new API, new regions, and new signals. 

  1. Transition Guide for APIv2 -> APIv3
  2. APIv3 documentation
  3. Release notes related to the API, data models, and methodology
  4. Data Signals Overview to explain each of the data types we offer
  5. Methodology & Validation have been updated and expanded

Support Webinar

WattTime will host a Q&A webinar about the new API and new features on Tuesday, January 23, at 11:30 a.m. PST / 2:30 p.m. EST. Learn more and sign up for the webinar here, and if you miss the webinar, the recording will be accessible on-demand using the same page after the event concludes.

API Version 2 Support

API v2 will continue to be supported until June 2024. While your upgrade to API v3 will be optional for approximately the next six months, we encourage you to proactively plan for your transition so that we can support you along the way if needed.

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