The economic value of trees in the urban forest as climate changes

The aesthetic value of trees in the avenues, boulevards and gardens of Australian cities is widely appreciated, but their economic significance is undervalued. Trees provide services and fulfill functional roles in cities. They are significant components of urban infrastructure and have a real and calculable economic value. An urban forest of 100,000 trees can save $ 1.5 million per annum because their shade reduces electricity consumption and saves water. Shade can prolong the life of tarmac, and carbon is sequestered as trees grow. A large tree growing in a school provides the equivalent shade of four shade sails, returning a value of about $ 2000 per annum, while five trees stabilize a steep suburban block which would otherwise require about $ 50,000 of engineered piling to secure building insurance. The shade provided by trees in mitigating the urban heat island effect is recognized, but what is its economic value? How many heatwave related excess deaths and ambulance call-outs can be saved as a consequence of the urban forest? The urban forest improving human health outcomes by fostering a 1-2% increase in passive/active recreation can save $ 274 million per annum in one Australian State alone. Calculation of the economic contributions of trees can change the economic algorithms upon which decisions are made. Public utilities should be undergrounded and street trees properly maintained. At a time of climate change, high density housing and inner city renewal are leading to a significant reduction in tree cover in major cities, which comes at a significant economic cost to urban infrastructure.