Environment and development belong together, according to the unshakeable optimist. And now the 55-year-old is the highest appointed German at the United Nations.
Achim Steiner never talks about environmental policies without mentioning the nitty-gritty of economic development. This habit probably stems from his background and career path.
The 55-year-old has been in the trenches of environmental activism since before his service at the UN, including work with the Washington-based International Union for Conservation of Nature.
He's even devoted his professional life - for example, while working as secretary general of the World Commission on Dams (WCD) - to pet projects. In 2000, the WCD published a report showing how reservoirs posed dangers to the environment despite their importance for development. Notable for its holistic and sustainable approach, it is this viewpoint that Steiner brings to his new office.
The new face of UN environmental development faces the enormous task of pushing good leadership in poor countries to combat poverty and AIDS, while also tackling environmental and climate protection.
A big deal for Germany
It is only fitting that Steiner - a citizen of the world, the son of a German, raised in Brazil, multilingual, studied at Oxford, and spent time in London, in Germany, Africa and Asia, - has been tapped as the next president of the UN Development Programme (UNDP).
This Brazilian soy plantation is one of many examples of the global need for higher food production that is both sustainable and environmentally-friendly
He also headed the Nairobi-based UN Environment Programme (UNEP) until 2016.
For the German government, Steiner's new role carries great significance: he will become the highest ranking German at the United Nations. A point, which Development Minister Gerd Müller was quick to emphasize.
"Germany is taking on more responsibility. That's the message the world is receiving. Selecting Achim Steiner to lead the UN Development Programme shows a deep appreciation of this fact."
Others were simply proud upon hearing the news.
"I'm very happy about this. Steiner is exactly the right person for the office of the UNDP president with all of his experience, with his passion for development and with his dedication," German Foreign Minister Sigmar Gabriel said.
The UN had been considering other candidates, not just Steiner. France's environmental minister, Segolene Royal, was a final contender - and noticeably unhappy about the UN's selection.
UN Secretary-General Antonio Guterres had actually promised the job to a woman, Royal said. She speculated that the UN tapped Steiner due to Germany's role as an important donor for the UNDP, which relies on (voluntary) donations from individual nations.
"It's a shame," said Royal.
A Bangladeshi woman sorts through a heap of plastic recycling. Consumer culture is producing too much waste and is a hazard to the environment
Tough shoes to fill in Nairobi
Contrary to Royal's insinuations, Steiner won't need Germany as a financial back-up, even if the UNDP must reckon with less cash from the United States. US President Donald Trump wants to lower his country's annual contributions to the UN by $325 million (303 euros).
But this particular appointment has nothing to do with the prospect of an increase in German funding. When Steiner became the head of the UN Environment Programme, he inherited a difficult situation. His predecessor Klaus Töpfer - a well-connected ex-German environment minister - set a precedent during his time in Nairobi, bringing the topic of climate change into the global discussion. As part of that legacy, Steiner saw his rise from $7 billion to $21 billion.
After his time in Nairobi, he applied for the post of UN Refugee Commission - to no avail.
Relying on some $60 billion a year primarily from G7 countries, the new face of UN environmental development faces the enormous task of pushing good leadership in poor countries to combat poverty and AIDS, while also tackling environmental and climate protection.