The Vatican confirmed this week that Pope Francis' encyclical letter on the environment is now finalized and is being translated, with an expected release date in June. An encyclical letter is considered the most important form of papal teaching. This will be the first-ever encyclical entirely devoted to the environment, and it is expected to call for urgent action to limit greenhouse gas emissions.

The announcement came during a Rome summit on climate change co-sponsored by the Vatican and the United Nations, headlined by UN Secretary-General Ban Ki-moon and Cardinal Peter Turkson of Ghana, president of the Pontifical Council for Justice and Peace.

Action on climate change a moral imperative

At the conclusion of the summit, more than 100 world leaders issued a statement in which they say decisive action to deal with climate change is "a moral and religious imperative for humanity".

Climate change deniers have reacted angrily to the Pope's planned encyclical. Could it have a major impact on climate denial in the US?

Full text: Declaration of Religious Leaders, Political Leaders, Business Leaders, Scientists and Development Practitioners (28 April 2015)

We the undersigned have assembled at the Pontifical Academies of Sciences and Social Sciences to address the challenges of human-induced climate change, extreme poverty, and social marginalisation, including human trafficking, in the context of sustainable development. We join together from many faiths and walks of life, reflecting humanity's shared yearning for peace, happiness, prosperity, justice, and environmental sustainability. We have considered the overwhelming scientific evidence regarding human-induced climate change, the loss of biodiversity, and the vulnerabilities of the poor to economic, social, and environmental shocks.

In the face of the emergencies of human-induced climate change, social exclusion, and extreme poverty, we join together to declare that: Human-induced climate change is a scientific reality, and its decisive mitigation is a moral and religious imperative for humanity; In this core moral space, the world's religions play a very vital role. These traditions all affirm the inherent dignity of every individual linked to the common good of all humanity.

They affirm the beauty, wonder, and inherent goodness of the natural world, and appreciate that it is a precious gift entrusted to our common care, making it our moral duty to respect rather than ravage the garden that is our home; The poor and excluded face dire threats from climate disruptions, including the increased frequency of droughts, extreme storms, heat waves, and rising sea levels; The world has within its technological grasp, financial means, and know-how the means to mitigate climate change while also ending extreme poverty, through the application of sustainable development solutions including the adoption of low-carbon energy systems supported by information and communications technologies;The financing of sustainable development, including climate mitigation, should be bolstered through new incentives for the transition towards low-carbon energy, and through the relentless pursuit of peace, which also will enable the shift of public financing from military spending to urgent investments for sustainable development.

The world should take note that the climate summit in Paris later this year (COP21) may be the last effective opportunity to negotiate arrangements that keep human- 2 induced warming below 2-degrees C, and aim to stay well below 2-degree C for safety, yet the current trajectory may well reach a devastating 4-degrees C or higher; Political leaders of all UN member states have a special responsibility to agree at COP21 to a bold climate agreement that confines global warming to a limit safe for humanity, while protecting the poor and the vulnerable from ongoing climate change that gravely endangers their lives.

The high-income countries should help to finance the costs of climate-change mitigation in low-income countries as the high-income countries have promised to do; Climate-change mitigation will require a rapid world transformation to a world powered by renewable and other low-carbon energy and the sustainable management of ecosystems. These transformations should be carried out in the context of globally agreed Sustainable Development Goals, consistent with ending extreme poverty; ensuring universal access for healthcare, quality education, safe water, and sustainable energy; and cooperating to end human trafficking and all forms of modern slavery; All sectors and stakeholders must do their part, a pledge that we fully commit to in our individual capacities.

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