"Momentum for Change: Climate Neutral Now" is an initiative launched by

"Momentum for Change: Climate Neutral Now" is an initiative launched by the UNFCCC Secretariat (United Nations Framework Convention on Climate Change). This initiative encourages individuals, companies, and organizations to measure their climate footprint, reduce it as much as possible, and offset the remainder by purchasing UN-certified carbon credits. Its goal is to encourage all parts of society to achieve climate neutrality.

The other options are incorrect:

A) The Intergovernmental Panel on Climate Change (IPCC): The IPCC is the leading international body for assessing climate change. It does not launch initiatives but provides scientific assessments. B) The UNEP Secretariat (United Nations Environment Programme): UNEP is a leading global environmental authority, but this specific initiative is under the UNFCCC. D) The World Meteorological Organization (WMO): WMO is dedicated to international cooperation and coordination on the state and behavior of the Earth's atmosphere, its interaction with the oceans, the climate it produces, and the resulting distribution of water resources. It is not responsible for this particular initiative.