Trees in Cities Challenge

2050, two-thirds of huma­ni­ty will be living in urban areas. Cities are a major dri­ver of cli­mate change, res­pon­sible for an esti­ma­ted 75% of all car­bon dioxide emis­sions glo­bal­ly but at the same time, they are par­ti­cu­lar­ly vul­ne­rable to its effects. Inland and coas­tal floo­ding, heat stress, extreme pre­ci­pi­ta­tion, droughts, water scar­ci­ty, and increa­sed air pol­lu­tion are just some of the expec­ted impacts.

Cli­mate risks are une­ven­ly dis­tri­bu­ted, both within and bet­ween cities. Cities with out­da­ted infra­struc­ture, urban sprawl, inade­quate hou­sing regu­la­tions and sup­ply, are at par­ti­cu­lar­ly high risk. Buil­ding urban resi­lience to cli­mate change is a com­plex, mul­ti- sta­ke­hol­der dri­ven pro­cess, and is often constrai­ned by the lack of resources.
In this context, nature-based solu­tions are both cost-effec­tive and sca­lable. They simul­ta- neous­ly miti­gate cli­mate change and contri­bute to buil­ding resi­lience against cli­mate- rela­ted and natu­ral hazards. Urban and peri-urban trees and forests are one such solution.

Stra­te­gic, tai­lo­red and ambi­tious tree-plan­ting and streng­the­ning capa­ci­ties for sus­tai­nable mana­ge­ment of urban forests is a pal­pable way for local govern­ments to contri­bute to cli­mate action and the Sus­tai­nable Deve­lop­ment Goals (SDGs).

As we enter the UN Decade on Eco­sys­tem Res­to­ra­tion, hoping to ins­pire large-scale efforts to halt the des­truc­tion of natu­ral habi­tats and res­tore degra­ded eco­sys­tems, this is the per­fect moment for city govern­ments to step in and contribute.

In 2019, the Uni­ted Nations Eco­no­mic Com­mis­sion for Europe (UNECE) laun­ched the “Trees in Cities Chal­lenge”. This ini­tia­tive invites mayors and local govern­ments world­wide to make a concrete tree-plan­ting pledge that will be imple­men­ted within a year and set up their objec­tives for making their cities gree­ner, resi­lient, and more sus­tai­nable. The “Trees in Cities Chal­lenge” will last until the end of 2022.

Mayors and local autho­ri­ties pled­ging under the “Trees in Cities Chal­lenge” are invi­ted to become part of a glo­bal com­mu­ni­ty of change-makers and offer their resi­dents bene­fits from the many eco­sys­tem ser­vices that trees and forests in and around cities provide.

For more infor­ma­tion, please visit

Project management:
UNECE/FAO Forestry and Timber Section
Project duration:
01.09.2019 –
Project partner:
Federal Office for the Environment FOEN