- Global CO2 emissions crept up by 0.9% (about 320 MT) to a new record high in 2022, according to a new report from the International Energy Agency – a slower growth than that of the economy, and thus perhaps a sign that renewable energy is starting to make a dent on carbon emissions. But do direct measurements through satellite observation support this finding?
- Like other global ”stocktakes”, the IEA’s is based on emission factors applied to a myriad government statistics on energy use and economic activity, plus data on heating and cooling degree days. To a large extent, the stocktake is only as good as the underlying data.
- A novel approach consists in using satellite imagery and other remote sensing techniques to directly measure high-emitting economic activity, from which associated CO2 emissions can be estimated independently of company and governments reports. Kayrros successfully applies it to a growing number of sectors and geographies, including all regulated sectors of the EU, as well as the UK and U.S., and all top carbon-intensive sectors of China: power generation, cement, steel and domestic aviation. How do the two approaches compare?
- To a large extent, the answer hinges on China, whose statistics have never been more uncertain than in 2022, when they showed both strong growth in overall coal demand and outright contraction or weak growth across all main coal consuming sectors. Kayrros measurements show emissions from the Chinese sectors it tracks plunged by an aggregate 520 MT, or more than 5% – a steeper decline than implied by official statistics.
- All other things being equal, the difference suggests global CO2 emissions could have inched downwards last year, not upwards as reflected in conventional stocktakes.
- While a decline in emissions might sound like good news, a drop due to stringent Covid-related measures could be more worrisome than it appears if it sets the stage for a steep rebound following the lifting of these measures, and thus for much faster growth in overall emissions than expected in 2023 – despite the continued buildout of renewable energy capacity.
Satellite data show China CO2 emissions plunged in 2022 in all key sectors
Figure: China CO2 emissions by sector based on satellite data analysis (Annual percentage change)
Kayrros analysis of satellite data show Chinese carbon emissions fell far more steeply in 2022 than suggested by official statistics and conventional CO2 emission assessments based on them.
- Last year’s drop spanned all key energy-intensive sectors monitored by Kayrros: coal power generation, cement and steel (monitored via satellite imagery) and domestic aviation (monitored through ADS-B signals).
- Kayrros reckons emissions from power generation fell by ~ 110 MT and those from industry by 390 MT.
- In contrast, the IEA, based on official statistics, reckons power generation emissions increased by 90 MT and fell by “only” 160 MT from industry. Kayrros measurements are 200 MT lower than the IEA’s for power generation and 230 MT lower for industry.
- In some sectors, the decline in emissions measured by Kayrros continued a trend. Thus, cement emissions have been continuously contracting for the last three years, but the pace of decline nearly doubled in 2022. Likewise, steel emissions, after initially rising in 2020, have since been on an accelerating downtrend.
Aggregate CO2 emissions from key Chinese sectors fell by > 5% last year
Figure: Kayrros China CO2 emissions aggregated index
In aggregate, analysis of satellite data shows CO2 emissions from all energy-intensive sectors of the Chinese economy monitored by Kayrros plunged by 520 MT or 5.20% last year, compared with the IEA assessment of a 0.2% dip in Chinese emissions. While that estimate covers China as a whole, the four sectors tracked by Kayrros loom large in China’s overall footprint and account for most of the annual change.
- Commentators and analysts often call Chinese official statistics into question, and this was especially true last year when there were unusual delays in releasing certain economic data – hence the value of direct satellite measurements. In particular, environmental scientists and researchers took note of a seeming contradiction in 2022 data between official reports of relatively robust growth in overall coal demand and of outright contraction or much slower growth in all key coal-consuming sectors.
- A large difference in the assessment of China’s footprint carries obvious implications, given the size of the Chinese economy, for the global carbon stocktake. If the aggregate drop in Chinese emissions measured by Kayrros were to be extrapolated to the whole Chinese economy, the difference with the IEA estimate, all other things being equal, would translate into a notable decline in global carbon emissions, compared to the IEA assessment of 0.9% growth.
Other regions show differences between satellite CO2 measurements and projections based on official data
Figure: EU total ETS Emissions
Differences in emission estimates between satellite-based measurements and estimates derived from emission factors may also be found in other regions. In Europe, where Kayrros tracks all CO2 regulated sectors, Kayrros reckons CO2 emissions rose by 1.9% last year, rather than fell by 2.5% as suggested by the IEA.
- Rising gas prices following Russia’s invasion of Ukraine sent industrial emissions, notably of cement and steel, even lower than they had been in 2020, at the peak of the Covid lockdowns. But these declines were more than offset by gains in emissions from both coal- and gas-fired power generation, as well as steep growth in domestic aviation and road transportations.
- Kayrros realtime estimates of European emissions compare extremely favorably with data collected by the EU for all carbon-regulated sectors, however these data are published with a considerable lag.
In turbulent times, direct observation cuts through the noise
The difference between the assessments of China’s CO2 footprint derived from satellite imaging and from official data for 2022 exceeds in scope the IEA’s overall estimate of growth in global carbon emissions. All other things being equal, a steeper drop in Chinese emissions than reflected in official data would be enough to push the assessment of the global carbon footprint from growth to decline.
- It would also suggest that China’s stringent zero-Covid policies may have played a larger role in curtailing overall emissions last year than the global expansion of wind and solar PV power generation capacity. This could lead to a stronger than expected rebound this year following the lifting of China’s Covid measures.
- At times of rapid shifts in industry and market turmoil, direct measurements through satellite observation consistently prove a more reliable way of monitoring supply chains and the climate footprint than official statistics, which typically struggle to keep up with the change. It is also much faster. Kayrros assessments of carbon emissions are realtime, and its 2022 stocktake was available on January 1st, months ahead of conventional reports.
Uzalishaji wa CO2 ulimwenguni uliongezeka kwa asilimia 0.9 (takriban milioni 320) hadi kiwango kipya cha rekodi mnamo 2022, kulingana na ripoti mpya kutoka Shirika la Nishati la Kimataifa (IEA), ambayo ni ukuaji wa polepole kuliko uchumi, na kwa hivyo labda ishara kwamba nishati mbadala inaanza kupunguza uzalishaji wa kaboni. Lakini je, vipimo vya moja kwa moja kupitia uchunguzi wa satelaiti huunga mkono ugunduzi huo? Kama ilivyo kwa "kuchunguza" nyingine za kimataifa, IEA inategemea sababu za uzalishaji zinazotumika kwa takwimu nyingi za serikali juu ya matumizi ya nishati na shughuli za kiuchumi, pamoja na data juu ya joto na baridi digrii-siku. Kwa kiasi kikubwa, hesabu ni nzuri tu kama data ya msingi. Njia mpya ni kutumia picha za satelaiti na mbinu nyingine za uchunguzi wa mbali kupima moja kwa moja shughuli za kiuchumi zenye uzalishaji mkubwa, ambazo kutoka kwa uzalishaji wa CO2 unaohusiana naweza kukadiriwa bila ripoti za kampuni na serikali. "Kayloros inafanikiwa kuitumia kwa idadi inayoongezeka ya sekta na maeneo, ikiwa ni pamoja na sekta zote zilizodhibitiwa za EU, pamoja na Uingereza na Marekani, na sekta zote za juu za kaboni za China: uzalishaji wa umeme, saruji, chuma na anga ya ndani. """ Mbinu hizo mbili zinafananaje? "Kwa kiasi kikubwa, jibu linategemea China, ambayo takwimu zake hazijawahi kuwa na uhakika zaidi kuliko mwaka wa 2022, wakati zilionyesha ukuaji mkubwa katika mahitaji ya jumla ya makaa ya mawe na kupungua kabisa au ukuaji dhaifu katika sekta zote kuu za matumizi ya makaa ya mawe. """ Uchunguzi wa Kayros unaonyesha uzalishaji kutoka kwa sekta za China ambazo zinafuatilia umepungua kwa jumla ya 520 MT, au zaidi ya 5% - kupungua kwa kasi kuliko ilivyoelezwa na takwimu rasmi. Kwa hali nyingine zote zikiwa sawa, tofauti hiyo inaonyesha uzalishaji wa CO2 ulimwenguni pote ungeweza kuwa umepungua mwaka jana, sio kuongezeka kama inavyoonyeshwa katika hesabu za kawaida. Ingawa kupungua kwa uzalishaji kunaweza kuonekana kama habari nzuri, kupungua kwa sababu ya hatua kali zinazohusiana na COVID-19 kunaweza kuwa na wasiwasi zaidi kuliko inavyoonekana ikiwa inaweka hatua ya kupona kwa kasi baada ya kuondolewa kwa hatua hizi, na kwa hivyo kwa ukuaji wa haraka zaidi katika uzalishaji wa jumla kuliko inatarajiwa katika 2023. Takwimu za satelaiti zinaonyesha uzalishaji wa CO2 wa China ulipungua sana mnamo 2022 katika sekta zote muhimu. (Mfano: Uzalishaji wa CO2 wa China kwa sekta kulingana na uchambuzi wa data ya satelaiti (Mabadiliko ya asilimia ya kila mwaka) Uchambuzi wa Kayros wa data ya satelaiti unaonyesha uzalishaji wa kaboni wa China ulipungua sana mnamo 2022 kuliko ilivyopendekezwa na takwimu rasmi na tathmini za kawaida za uzalishaji wa CO2. - Kupungua mwaka jana ulizunguka sekta zote muhimu za nishati-intensive kufuatiliwa na Kayrros: makaa ya mawe ya umeme, saruji na chuma (kufuatwa kupitia picha za satelaiti) na anga ya ndani (kufuatwa kupitia ishara ADS-B). Kwa mujibu wa ripoti ya shirika la Kimataifa la Kimataifa, uzalishaji wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme wa umeme. Kwa upande mwingine, IEA, kulingana na takwimu rasmi, inakadiria uzalishaji wa umeme uliongezeka kwa MT 90 na ilipungua kwa MT 160 tu kutoka kwa viwanda. Kiwango cha K2 ni chini ya kiwango cha IEA kwa uzalishaji wa umeme na chini ya kiwango cha IEA kwa viwanda. - Katika sekta fulani, kupungua kwa uzalishaji ulipimwa na Kayrros iliendelea mwelekeo. Kwa hivyo, uzalishaji wa saruji umekuwa ukipungua kwa miaka mitatu iliyopita, lakini kasi ya kupungua karibu mara mbili mnamo 2022. Kwa upande mwingine, uzalishaji wa chuma, baada ya kuongezeka kwa kwanza mnamo 2020, umekuwa kwenye mwenendo wa kupungua. "Kichwa cha habari cha IEA, ""Kayros China CO2 Emissions Aggregate Index"" inaonyesha kwamba, kwa jumla, uchambuzi wa data ya satelaiti unaonyesha uzalishaji wa CO2 kutoka kwa sekta zote za uchumi wa China zinazotumia nishati nyingi, zinazofanyiwa uchunguzi na Kayros, ulipungua kwa milioni 520 (5,20%) mwaka jana, ikilinganishwa na tathmini ya IEA ya kupungua kwa uzalishaji wa China." Ingawa makadirio hayo yanajumuisha China kwa ujumla, sekta nne zilizochunguzwa na Kayros zinaonekana kuwa kubwa katika alama ya jumla ya China na zinawakilisha mabadiliko mengi ya kila mwaka. - Wachambuzi na wachambuzi mara nyingi huuliza takwimu rasmi za China, na hii ilikuwa kweli hasa mwaka jana wakati kulikuwa na ucheleweshaji usio wa kawaida katika kutolewa kwa data fulani za kiuchumi - kwa hivyo thamani ya vipimo vya moja kwa moja vya satelaiti. Wanasayansi wa mazingira na watafiti waliona utata wa data ya 2022 kati ya ripoti rasmi za ukuaji wa nguvu katika mahitaji ya jumla ya makaa ya mawe na kupungua kwa moja kwa moja au ukuaji wa polepole zaidi katika sekta zote muhimu za matumizi ya makaa ya mawe. - Tofauti kubwa katika tathmini ya alama ya China ina athari dhahiri, kutokana na ukubwa wa uchumi wa China, kwa hifadhi ya kaboni ya kimataifa. "Ikiwa kupungua kwa jumla kwa uzalishaji wa kaboni nchini China, kama ilivyoelezwa na Kayros, kunapaswa kuendelezwa kwa uchumi wote wa China, tofauti na makadirio ya IEA, vitu vingine vyote vikiwa sawa, ingeweza kutafsiriwa kuwa kupungua kwa uzalishaji wa kaboni ulimwenguni, ikilinganishwa na tathmini ya IEA ya ""kukuza kwa 0.9%.""" Mipaka ya CO2 ya satellite na makadirio ya EU ya CO2 ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU ya EU. Katika Ulaya, ambapo Kayros hufuatilia sekta zote zinazodhibitiwa na CO2, Kayros anadhani uzalishaji wa CO2 uliongezeka kwa 1.9% mwaka jana, badala ya kupungua kwa 2.5% kama ilivyopendekezwa na IEA. Kuongezeka kwa bei ya gesi baada ya uvamizi wa Urusi wa Ukraine ulifanya uzalishaji wa viwanda, haswa saruji na chuma, kuwa chini kuliko ilivyokuwa mnamo 2020, wakati wa kilele cha kufungwa kwa Covid-19. Lakini kupungua huko kulipunguzwa zaidi na ongezeko la uzalishaji wa umeme unaotokana na makaa ya mawe na gesi, pamoja na ukuaji mkubwa katika usafiri wa anga wa ndani na usafiri wa barabara. Makadirio ya wakati halisi ya uzalishaji wa Ulaya ya Kayros yanalingana vizuri sana na data zilizokusanywa na EU kwa sekta zote za kaboni, hata hivyo data hizi zinachapishwa na kuchelewa sana. "Kutokana na uchunguzi wa moja kwa moja, tofauti kati ya tathmini ya alama ya CO2 ya China inayotokana na picha za satelaiti na data rasmi kwa 2022 inazidi ""ukadiriaji wa jumla wa IEA wa ukuaji wa uzalishaji wa kaboni ulimwenguni.""" Kwa hali nyingine zote zikiwa sawa, kupungua kwa uzalishaji wa China kuliko ilivyoonyeshwa katika data rasmi kungekuwa na kutosha kushinikiza tathmini ya alama ya kaboni ya ulimwengu kutoka kwa ukuaji hadi kupungua. "Hii pia inamaanisha kuwa sera kali za ""zero-Covid"" za China zinaweza kuwa na jukumu kubwa katika kupunguza uzalishaji wa jumla mwaka jana kuliko upanuzi wa kimataifa wa uwezo wa uzalishaji wa umeme wa upepo na jua." Hii inaweza kusababisha kupona kwa nguvu kuliko ilivyotarajiwa mwaka huu kufuatia kuondolewa kwa hatua za Covid za China. Katika nyakati za mabadiliko ya haraka katika sekta na misingi ya soko, vipimo vya moja kwa moja kupitia uchunguzi wa satelaiti mara kwa mara kuthibitisha njia ya kuaminika zaidi ya ufuatiliaji wa minyororo ya usambazaji na alama ya hali ya hewa kuliko takwimu rasmi, ambayo kwa kawaida hujitahidi kuendelea na mabadiliko. Pia ni ya haraka zaidi. "Kayros inatoa ripoti za ""wakati halisi"" na ""wakati wa 2022"" kwa mujibu wa ripoti ya mwaka huu."