美國加州州長布朗（Jerry Brown）警告，人類對地球的傷害程度令人憂心，讓地球快速接近（不可逆的）臨界點；為此他在23日參加了由超過500位科學家共同出席的集會，呼籲針對氣候變遷和其他影響人類的全球性威脅展開行動。
布朗說道，「這並只是關乎科學，更關乎行動。這是個重要的挑戰、理想與承諾。我們做得到，但我們必須要付出比現在更多的努力！」
不過，值得一提的是，加州環保人士也對布朗感到失望，認為他並未進一步行動來減少加州的溫室氣體排放。這是指加州最近的決策──為了平衡州政府預算，布朗決定以州立法通過的溫室氣體排放法律，釋出500萬美元的碳交易額度。
布朗和科學家簽署聲明呼籲採取行動的場合，是在山景城舉辦的第四屆之年度水源、能源和智能科技（Water, Energy, Smart Technology，簡稱WEST）高峰會，同時，美國太空總署（NASA）艾姆斯研究中心的展示會也在同場地舉行。WEST高峰會是「永續矽谷組織」每年最大的活動，是為了實踐組織的目標：帶領整個矽谷社群邁向永續。
這份長達20頁的共識聲明由州長提出、500位科學家簽署，聲明當中把各領域關鍵的科學研究整合成一份統一的資料，提供給決策者、企業和人民。目標是促進氣候變遷相關科學研究與政治行動的連結。
聲明中提出5大棲息環境的關鍵威脅和解決方向，決策者必須現在就想辦法解決，以避免人類的健康與繁榮退化：
- 氣候變遷：預報顯示地球溫度將在2070年達到人類從未體驗過的高溫。
- 物種滅絕：依照現在物種滅絕的速度，我們將會在短短3個世紀內失去75%的脊椎動物。
- 生態系統崩壞：在2012年，超過40%的無冰地區因人類的活動而改變，這導致了生物滅絕，也對地球的生物多樣性造成影響。
- 污染：環境中不斷增加的有毒物質，讓超過1億人直接暴露在健康問題的風險下。
- 人口成長和人口總數：人口成長進而製造更多的溫室氣體和有毒污染物，導致全球環境崩壞，也使得生態系統產生變化。
完整的聲明，和簽署聲明的500位科學家的名單都可以在《人與生物圈千禧年同盟》的網站中看到。
Warning that Earth is rapidly approaching a tipping point at which human impacts are causing alarming levels of harm to our planet, California Governor Jerry Brown today joined more than 500 scientists to release a call to action on climate change and other global threats to all humanity.
"This is not just about science, this is about activism," said Governor Brown. "This is an important challenge, cause and undertaking. We can do it, but we have to do a lot more than we're doing now."
But California environmentalists are disappointed that Governor Brown is not doing more to reduce greenhouse gas emissions in his own state.
They are critical of the governor's decision to use $500 million of cap-and-trade revenue collected under California's groundbreaking law governing these emissions, to balance the state budget.
Governor Brown and the scientists released the call to action at the fourth annual Water, Energy and Smart Technology Summit and Showcase at NASA Ames Research Center in Mountain View.
The WEST Summit is Sustainable Silicon Valley's largest annual event, serving the organization's mission to lead the Silicon Valley community to a more sustainable future.
The 20-page consensus statement, produced at the governor's urging and signed by more than 500 concerned scientists, translates key scientific findings from disparate fields into one unified message for policymakers, industry and the general public.
This statement aims to improve the connection between scientific research and political action on climate change.
The call to action identifies five key threats to the habitable environment that policymakers must address now to avoid the degradation of humanity's relative health and prosperity along with broad solutions to the challenges outlined:
- Climate change – Forecasts show that Earth will be hotter than the human species has ever experienced by the year 2070.
- Extinctions – At the current rate of species extinction, the world will see the loss of 75 percent of vertebrate species within as little as three centuries.
- Loss of ecosystems – As of 2012, more than 40 percent of Earth's ice-free lands have been changed by human activity, causing species extinction and other impacts to Earth's biodiversity.
- Pollution – Increasing levels of toxic substances in the environment put over 100 million people at direct risk of health problems.
- Population growth and consumption – Human population growth contributes to global environmental disruption by adding greenhouse gases and toxic pollutants to the environment and altering ecosystems.
The full text of the statement and the list of the more than 500 scientists who signed the document are available on the Millennium Alliance for Humanity and the Biosphere website.
http://mahb.stanford.edu/consensus-statement-from-global-scientists/
※ 全文及圖片詳見：ENS
