CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "www.iea.org",cType: 'managed',cRay: '91ff91651b163e4f',cH: 'ivDC_rYJKctv3VlGCT3lqY9EQm4SA3h62IW2h92P170-1741911235-1.2.1.1-xG8VMEjpELYKg9ChU.5Kya.jvxFZzIednaDZn6.7sRu0Edyawie_sTdKLelOc6G7',cUPMDTk: "\/glossary?__cf_chl_tk=GMypwSxevGo4FD1ZSFRlv8hB3fKd_kflJjCa1PHr0W8-1741911235-1.0.1.1-F_zZnYowjUTODgpJGz0tzNPNYpEHj9laFmocAZ.YuK8",cFPWv: 'g',cITimeS: '1741911235',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/glossary?__cf_chl_f_tk=GMypwSxevGo4FD1ZSFRlv8hB3fKd_kflJjCa1PHr0W8-1741911235-1.0.1.1-F_zZnYowjUTODgpJGz0tzNPNYpEHj9laFmocAZ.YuK8",md: "Maq0D23tkln_IPEqVULYPuBtOjhB9IGpKumXNmEJGyM-1741911235-1.2.1.1-JfTR2c9cPLOC40Qtifz9PH2jQ4ZCO42ghjQomoiTQ4ZQL50aJXNElYcsVq80ho.bK42Ga_x_UlJ4uik9rI9Y7AEn6K3aLeswadddAs72R6DupgIEdI9E3dtlY0btHZlGx3YcK1V6GvDRdW4teVsjJZ6Skn8WnokfnbWtPWV0TNsdoR_MzvJo5JEfSDgcelWGnZgbhY0Vw4lbfjzxNuBrIn.mxcjCOfuXHHusAJQdcjUnOl5vwMHSQHuPj_B2D0pVI4pi3bpijymotO.3Hk7npH649j3W67APQQ03VU3OE4Wi1SMzsVPHnBCzUvi0Nsthv4QLiNC270Ei6Zfj8FUlcnSSKu3gyoPeDk525XCRnnMoVvdhnZteJnK7zhVINiChnEYQHSWzsD7fhEI5P432eENYhd7lPph5kuFKwKq7Y2OK4MaIa.yoofewebXcE49F1bu8O.y7jJYQb_Jh_jvFwCAE0BIvD2ZbOa858_UvCSM7xTXnYhBX81TxcfxTg99PmzSNZVYRBVPojoYB9EEVmp.9ks5.gZq5yS7lLVlmA1mapanR9CGaM2sqdWV6CRkfLLeLDyaNTGyYZ2zvRPQD.5pHuWmPS_mtZVuU7BZJ64Rf4m_lL1cwuIWQxEkPb65mJmOm5MnCKt4D0Ipw4BfVdTtDyoH7jIho8PRRGLvPDr1JNkulSob6yroOn5s54seHTbX2b9gjUguE41amakEs9y1phkPC4ROCb59mvsNxZsb3b1enRxox1pEj7EDRWUWocdqXxScqm._4aC0NXlV1oZhkU8lXZyQId9MtxivjzBkpJtuqd3AhCG77DWz4wRgTiVAplVGbRY0X3YFsjf.ctY3cM.4AN8JFC4fBgfnpClPuel77HeEU8d8lZ4xEQMUQliD2DgFg5HelSDoPT2V3pUsuzPiLIGDgfFbaBJd1cc75xyas4RRzThyOL_0cMXvUYPPKqAR9hTea48KjICZOvF3lK338HgUBilKpnHzDaevP6RkH8OpB8rZyEyfKKu4qi4hmEPiSc1q1etoQljGT478u0b4XXt0WV6vSebIH7lN7roX1qM8cgiB0tdCl68E99RcUA2uEC.1jWzaO5amZt0x.jGZLHgaLCRlEhgTXqPpwkdBG8MQnNDnp2DUcRI1tl5Wpp4LMqANsa1Qm02uKx.sPXRAm79TYZpnsQ.2Npuk",mdrd: "wIAsX_3yjXPtx0VQofnDdIy8gLpDv0UwZz3SBNp11eQ-1741911235-1.2.1.1-D7fLjsGKS4Er2O1NHqTyo3lH2HdGE8dCUZladwtMv4QEER7eIk5p_uUZhPpj..t3Y7f0.0Xwsws5YIsZBk3sLnEb2iiXSVt2U6pW1aQ4vf9tFzjHaWdk4ntjoloKvdUIZZgJdrr4c3D6PhdLRKXQ2BdwZzfydqi_GoAttmhwVNlMXN43KR0WSfm5GaAEo7mr4cghznd5uBFeNlMTO1aw52C876YfzeZp7.UDFPOtizyYfwCNIsYq8u9Lfn0_r6INdiV7X_SDaoanK3245sdB29Uau0UGmdMqRSQr0QEorDlHw5wbs9wvhnGxWbir7iBxCy6xQeO4yP6ymg1v0nMIXPOfwEfvOXRT7fdlOxm_fe5YHc7Wni3_t2FOWd27lZO6xvqs5Gkc70NmEqlz12dGp54gXKbVRXB_yBRjUKMhSk0X75MnDU0pHNlkOK2PoRjS07EjI8FEYyaJ4HuSTCztvDa9bbaItaqOqWzt4Ng2Sk2jRWng4yEHftwPxE8TarKHuD9pXLsUNovV0qdPi79TntVyGWRlC4JZ8EVS6t5QVQUTcscMBv5q7gQhu4wuTnJ3IkE46DdyTdqiO20vST2a0x3CFUUU.5pEUBBORcWGxQM2XIrgaZHtvHlCNYBQrwQNGZx_Ezfj9DD8tKRCZddDiQcupMaK7ScQGNyElGDo5FW2a.5X_avJez4aQ8RqH5Hc"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=91ff91651b163e4f';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/glossary?__cf_chl_rt_tk=GMypwSxevGo4FD1ZSFRlv8hB3fKd_kflJjCa1PHr0W8-1741911235-1.0.1.1-F_zZnYowjUTODgpJGz0tzNPNYpEHj9laFmocAZ.YuK8" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>