In ancient times, Lebanon was covered by large forests of cedar trees, the national emblem of the country. Millennia of deforestation have altered the hydrology in Mount Lebanon and changed the regional climate adversely. As of 2012, forests covered 13.4% of the Lebanese land area; they are under constant threat from wildfires caused by the long dry summer season.
As a result of longstanding exploitation, few old cedar trees remain in pockets of forests in Lebanon, but there is an active program to conserve and regenerate the forests. The Lebanese approach has emphasized natural regeneration over planting by creating the right conditions for germination and growth. The Lebanese state has created several nature reserves that contain cedars, including the Shouf Biosphere Reserve, the Jaj Cedar Reserve, the Tannourine Reserve, the Ammouaa and Karm Shbat Reserves in the Akkar district, and the Forest of the Cedars of God near Bsharri. Lebanon had a 2019 Forest Landscape Integrity Index mean score of 3.76/10, ranking it 141st globally out of 172 countries.
In 2010, the Environment Ministry set a 10-year plan to increase the national forest coverage by 20%, which is equivalent to the planting of two million new trees each year. The plan was inaugurated in 2011 by planting cedar, pine, wild almond, juniper, fir, oak and other seedlings, in ten regions around Lebanon. As of 2016, forests covered 13.6% of Lebanon, and other wooded lands represented a further 11%. Since 2011, over 600,000 trees, including cedars and other native species, have been planted throughout the country as part of the Lebanon Reforestation Initiative,
Lebanon contains two terrestrial ecoregions: Eastern Mediterranean conifer-sclerophyllous-broadleaf forests and Southern Anatolian montane conifer and deciduous forests.
Beirut and Mount Lebanon have been facing a severe garbage crisis. After the closure of the Bourj Hammoud dump in 1997, the al-Naameh dumpsite was opened by the government in 1998. The al-Naameh dumpsite was planned to contain 2 million tons of waste for a limited period of six years at the most. It was designed to be a temporary solution, while the government would have devised a long-term plan. Sixteen years later al-Naameh was still open and exceeded its capacity by 13 million tons. In July 2015 the residents of the area, already protesting in the recent years, forced the closure of the dumpsite. The inefficiency of the government, as well as the corruption inside of the waste management company Sukleen in charge of managing the garbage in Lebanon, have resulted in piles of garbage blocking streets in Mount Lebanon and Beirut.
In 2017, Human Rights Watch found that Lebanon's garbage crisis, and open burning of waste in particular, was posing a health risk to residents and violating the state's obligations under international law.
In September 2018, Lebanon's parliament passed a law that banned open dumping and burning of waste. Despite penalties set in case of violations, Lebanese municipalities have been openly burning the waste, putting the lives of people in danger. In October 2018, Human Rights Watch researchers witnessed the open burning of dumps in al-Qantara and Qabrikha.
On Sunday 13 October 2019 at night, a series of about 100 forest fires according to Lebanese Civil Defense, broke out and spread over large areas of Lebanon's forests. Lebanese Prime Minister Saad Al-Hariri confirmed his contact with a number of countries to send assistance via helicopters and firefighting planes, Cyprus, Jordan, Turkey and Greece participated in firefighting. According to press reports on Tuesday, fire has decreased in different places due to the rains.