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: "news.sciencemag.org",cType: 'managed',cRay: '92a8ea525dfca07e',cH: 'pywt.7sxG8cm3_052J6mVY1b9bWbX3kddiox3xEq6FA-1743686971-1.2.1.1-LhHrcY3bsKMcW93Vrnqse760K4LxREfPc1lBdRgqWRdFDcQIgJxSbSelCzBMulX_',cUPMDTk: "\/environment\/2015\/08\/meat-eaters-may-speed-worldwide-species-extinction-study-warns?__cf_chl_tk=lrfQsTh7yW4TrygEr_2RR4jERPOznylTnYlvK6BAAAA-1743686971-1.0.1.1-1D3cihHt6b8HZZMu5vNvbU7YdDeNtgLdlDZd5pK9kuk",cFPWv: 'g',cITimeS: '1743686971',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/environment\/2015\/08\/meat-eaters-may-speed-worldwide-species-extinction-study-warns?__cf_chl_f_tk=lrfQsTh7yW4TrygEr_2RR4jERPOznylTnYlvK6BAAAA-1743686971-1.0.1.1-1D3cihHt6b8HZZMu5vNvbU7YdDeNtgLdlDZd5pK9kuk",md: "dTcyDCDGlvAbwacGepaZMkOnbHGjmlVxx.xHobTFhR8-1743686971-1.2.1.1-XdVr8gj7DsX5Ob3b6yEKOmiTWxMRY5_nIgmAQQvGHysdsdD28huSxpfGttEc5QzT.rBEUFSnnv_N2Jj6UfO2OXVzYQhf3NJ0b2_Kn0hogd861s4JBhi5Gw7RRHbjeIwfvrrsUNBvlDoCfq4M7Lr1xIcnsItNXQ41MYuQfYtCYNYi5BJPk8nULjL.13DQNbYte50IyBa9gjObEhrU4sR5QEEZlSvGiChzo76IHxJjBpbQUW6lX_SZHIkUsQIAnoBv4BkwePnEkOenANOYOkXF2bmwpUoOxnZ06PcKuW_QoosS0xHKrTWkrzxiXkCWM6PFdsUVxeI3RcnSc8AY145Z1q3.2AWHM8zgurzjVF7E6RHTb_qht7BSSvoYbKzQZ3GYVTRkuS.miRSMRBx3pbHac7MgukoKpw3xh5Pyn0vTk_FTOZqYQ9FYcUz8PbXhPDXvS87_20jCoASk3LkWqEcKn_F9vSaF6oJdoXpZi4io9pZqqd_BC_HLGEf05FVd3Qhf2G2IFVBaaxpcwxAkCu_VeXlKAjiP3s2zWdtW4JE53tCBNV8ToJ06.m4qUBASUzW2kUI0fp4eP7dzThayWKbpsdiAGEB0BxmWa.zjiV2J18.6eOejJHJWnWeI8e87_MO7hX.dWJojutzg8bFnxUEhDlKWst7zfUMcJvzvwlSpF4jhNvuXVR7NvhTXugvNHlacZ0_18nDCgAL2nZTRr5cDXvzlSMybLJDGxMZkOSp2gC81TAtugtENTEl3S9Cp2dXCc5GmH_2YkXBWs2jBCJEfeORfqIZLw.rYSYwKou1vpXTYHeVL0L39Iblgh0qVh1KCbX2Cf3Fi8paoKTpfCvOAnvDkYnPEJp1JsGmcNK5TOYhg3MXDAq7i3Xl9.SYJ4aS_GGzv7CLB2epu506DfyMAK4LtUjaQZwWwwf_tYvrrT7V.qT4fnlXaLYAuG9EmzITiIkI3yLZx4a_IIEKRD1Nijq7dQsptUSkzXabk2_j2inCA4n6NhqwzJnUVNeA3TpMEq7dfBEuWrf4FYExovxqa8ZLgx_c9_42qLhKHMRXSqGHsWMVdhuwvRTg56SDDoUepvbzzKjSxXFqTpKnRr_f_Eq1AsQikThX.UjfJRWTjHNnKA9TPF2wpLAN1Wj4SPTDP4Bt0_FK6slWvSX0I55Q60Zor9KvxI9ocmtq7zDPcThNYOkHSpYRL2jBevIPluNUpEwEOZDvFA1jm5o1vTdCymjPc6KBir3S25ewiLNA.GniV5TpQzmpn5_7.OkHZIcaZa8lXCmsRRUxjjvKi_IvohkG2ra4H0cdMGpwz6cr1InqRV7fvxz.3fAGE1bmd5ugU.giid8muV2zPNPsOfoRdBu.oLQz.y.t7BPYOoTv5iDSL7SPyCJ_p2XBgmOk_wCRSKY.i9beeuEmFWLMnBetDnALpUGlvs9u4tCZl..AxKRE",mdrd: "w_JnvM1bxUmk9QamlEsf7.IOT9jzp7zpjiWa2nsH4HM-1743686971-1.2.1.1-ROdnRuYlWkpF2Ioeh3890eX6hJLvTA_M4z_yhIHVdv056IcAhGTE4BHg6CCpxxAnEechXzUf6u7zelREZc6JhgPPTJy51ltRsnT4cOsBiq7Rik_wAr2OYqoF_w6fld3Rg0_9AHbaBGkZZLXYtVyQeMPFLS4SjW3phfpX9LguiCXil_KLMG.gUGWkI7u3kyBZtKdmwTA3.aODidCrkDJEtBI7a8a2FQeWGsvYSa1czP8CGe_XblHvI_oDFACvQggc1jKx5LtcYin2I6eTexFfU0WjRVBCsH.7UYIN0Lu7Zb_tWIUVtSxHcDIIp.tmZ78zMadn_NCoZZkXwGu2PC2MbIL3P9Td4yopc.w40aLZLyhN91sPLHfv6.gZBFC51DAtKOqBN92kmdW0TOBS.4iyHLpYkeP0d.zxbeiaDW2n8uajFg0sxa1SFdHnJOheSpk7Uoqli5XHVyCEJ0ti5iyesG0o1Y5uhuz95n7f9UudSbV4rNxt_1KgDmICVrz.cZyfdAi8DzupmRT2A0K59vVIbfYd50mWraoxzrWJhcUKwKpfxEOZKOpD3kjJZ55OMrL3hkCQlDAIz2IlaqNMFqojdI220Bi3C3bbqNM5cnfkSRhyj1YRjUuvnh1dbV3FkeNFCQ7DfmIL4MDqpXty_pyUYNYUCP8RdRn4rKeIKozOlaW3qRVkYD07O0GHY1TivhSgpzYMZwkgdZwul3EwnbUvb_XxN2T_KiTqbj0mXMGHfN.3rqU7zjSjetJn3UDZC6J1QPf2tYj6z41NrrABhbrM340IRqbrUt42zKeru9VuV_CMzGeNbNYmiF79VtbObYKOnUvMWReo5EA658DSRyu.Q98J9RF3PsNP1OZ49sxWc0UPvzfJrSS8xDXh96xJLvDb2XeSk4Q9nXiNMOH1W1Z6CYBLECij1GkK1rf9VUc0T.QtUhnWkgbr9gpUlqf8ZWxhqbeOLQIehYsLLhcIG8IYOlJUzpKpCuetqhsAly2wubmvPXs5hnfXvnv4kcHuaJVCxGUV.jpdkkonpGknkiIc0qNa3jXaoNyzNimf5KgjVA97PfZYf9REbUj6ucBUpkmodEv59aDpavrkSbjLpIsuFVWIEnnJZCCkOWtDbg9K8S9k8dZWFEHu2PFifyfGEBgvZyRH3HF1E2BRGR6KSBPR6QAuOM0yz7tCOVpc4gXMvdF6kqi53plp97qKftjCurpS_1NQT1UfOu_7aZFPBWJfGoygfCJ59F4eIYXE0K2gkrIzm9icL.dKX_C4YKfbENDYlH9VJsmTlQ5zTh0vcDcigWCW1t.pJvLkIKovEa0EclJ8sspqdGM2it0O18En12gvk.mOQVF1bwjLWQbiZRI3BJNt8CuY9JPgETL00nTsUuGK3J0dj74F3oyHuN1Q0MynaMv6RXkjzRdfnSSeKo_YP7eZ5K8RlfJUJrzUIajckUNNW5cJizMJUy5feykbVaFyQkNodMO5c73Fl5tlvUrvvKBT9F3PFlh9_iVabP3gyhldpJxcX5ROMXpEOakvsVaQEWVPDE3A8jjmBJ7EBkrwqPhdk4LPuaP8F_FItnuKn.Pojpxha7EDupZ3NVPArIZ79CksQN0uq9pq2AmWkQF2bpKsaD5_is.lx8U4cTJ2NsdVc9IqE5TB25iaxf9PBwXrsdJWDC_AsJ3ihI1x8i426FkBMIozLSldgYQs6stOwDwFlEv84i1SSZtsy41KwVT1oaFFJAZxQNl3rg.9zttL3y_mMJWtamHzQAboxxhZI8_Lc_DuNTg.wKjxIWlXmH5QQlEGtISfzPQtEG3LLNMuZlT4uAnAFaGv_5cygvjze9As.ZXAXWL500YTEO7cB9l40EGG8iNaLZC9u2v29OB0yKSHpjaAXN3qYucRbEXa48_5EqoONWJNbBElOH7yCJFAZ9bYRqJ.WlhBzn2HTmhgG4pPiSCkaxDMwnWxzKtFCniFoe0MhN05hrTX1zsI_2etw62GLY6Vb1v2qIPbPPfJzTOENINWN5cRkHUpIcULhmdZVP68lbSSV3o0Gb9G7k1OhGVnqQyvl_zx_Eug.mlM3F7hyGXlimvRyy7jxGdYf4Q"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=92a8ea525dfca07e';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, "\/environment\/2015\/08\/meat-eaters-may-speed-worldwide-species-extinction-study-warns?__cf_chl_rt_tk=lrfQsTh7yW4TrygEr_2RR4jERPOznylTnYlvK6BAAAA-1743686971-1.0.1.1-1D3cihHt6b8HZZMu5vNvbU7YdDeNtgLdlDZd5pK9kuk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>