Karl is the Deputy Director of One Earth and formerly the Director of Media, Science & Technology at the Leonardo DiCaprio Foundation. One Earth's Science Program supports academic institutions and NGOs working on the cutting edge of climate and energy science, biodiversity conservation, and sustainable food systems. Through grantmaking and development capacity, the program helps to turn science into action, empowering decision-makers in government, civil society, and the private sector. Karl also oversees the production and distribution of content across One Earth’s website and social media properties, along with award-winning initiatives such as the Global Safety Net, which was recently named a "World Changing Idea" by Fast Company.
Karl is a contributing author to "A roadmap for repowering California for all purposes with wind, water, and sunlight" (Energy, 2014) and later spearheaded the development of the landmark textbook Achieving the Paris Climate Agreement Goals (Springer Nature, 2019). He is also co-author of “A Global Deal for Nature: Guiding Principles, Milestones, and Targets” (Science Advances, 2019), a scientific paper establishing the evidence base for an ambitious conservation agenda covering 50% of the world’s lands and seas, which was endorsed by the IUCN including a 30x30 interim target subsequently adopted by the 2022 UN Convention on Biological Diversity.