Qatar's One Million Trees Initiative — Treated-Wastewater Urban Afforestation & Green-Space Expansion

Qatar's Ministry of Municipality has run a sustained urban-greening programme since 2015, expanding the country's mapped green space from 3.5 square kilometres to 16.7 square kilometres by 2023, and increasing the number of managed parks from 56 (2010) to 143 (2023). The flagship element is a One Million Trees drive, launched around the 2022 FIFA World Cup and folded into a wider ten-million-tree target for 2030, using drought-tolerant native species -- Prosopis cineraria (ghaf), Ziziphus nummularia (sidr) and Acacia tortilis (samr) -- irrigated largely with treated sewage effluent rather than potable water.

The largest single site is a 94,043-tree forest on roughly 7.5 square kilometres beside the Doha North Wastewater Treatment Plant, reusing treated effluent that would otherwise need disposal.

Officials estimate the mature tree stock could absorb on the order of 1,700 tonnes of CO2 per day (roughly 1.7-2 kg per tree daily) -- a modelled estimate rather than a measured flux, and one not yet validated by independent monitoring. Qatar's own Ministry of Municipality climate-adaptation strategy separately flags heat-island reduction and green-space accessibility as priorities, giving the programme an explicit policy anchor beyond the tree count itself.

Reported figures come from government and government-adjacent press sources rather than peer-reviewed measurement, biodiversity outcomes of the mostly single-species plantings are not tracked publicly, and long-term water demand of a million more trees in an arid, desalination-dependent country has not been independently assessed.