This assessment is based on the Earth Overshoot Day (EOD) concept, which marks the date when humanity’s annual demand on nature exceeds what the earth’s ecosystems can regenerate that year.

This year, Vietnam’s EOD falls on October 8. A country’s overshoot day is the date on which EOD would fall if all of humanity consumed resources as the people of that country.

The EOD is calculated by the Global Footprint Network in a campaign supported by dozens of other nonprofit organizations.

Founded in 2003, Global Footprint Network is an independent think tank based in the U.S., Belgium and Switzerland. It operates to develop and promote tools for advancing sustainability, including the ecological footprint and bio-capacity, which measures the amount of resources we use and how much we have.

Vietnam’s EOD fell on December 21 last year, also the year when the country had the latest overshoot day in the world.

The EOD is calculated by dividing the world’s bio-capacity, or the amount of natural resources generated by Earth that year, by the world ecological footprint, the humanity's consumption of Earth's natural resources for that year, and multiplying it by 365, the number of days in one common calendar year.

Not all countries will have an overshoot day, according to Global Footprint Network.

A country will only have an overshoot day if their ecological footprint per person is greater than global bio-capacity. Countries whose ecological footprint per person are less than the global bio-capacity do not have an overshoot day and are therefore not included in the listing.

For this year, the global EOD has been calculated at July 29, meaning humanity had already used its natural resource budget for the entire year by that date.

The due date for this year has moved up by two months over the past 20 years and also marks the earliest date ever, Global Footprint Network said.

Humanity first saw ecological deficit in the early 1970s.

An ecological deficit occurs when the ecological footprint of a population exceeds the bio-capacity of the area available to that population.

A national ecological deficit means that the nation is importing bio-capacity through trade, liquidating national ecological assets or emitting carbon dioxide waste into the atmosphere. An ecological reserve exists when the bio-capacity of a region exceeds its population's ecological footprint.

For now, Vietnam is also running an ecological deficit, in which the ecological footprint exceeds bio-capacity by a whopping 108 percent, as calculated by the Global Footprint Network.

Joining Vietnam in posting massive ecological deficits in Southeast Asia are Thailand, Cambodia, the Philippines, Singapore, Indonesia, Malaysia and Brunei.

Myanmar, Laos and East Timor are with biocapacity reserves.

Vietnam is making progress on some ecology fronts though. In July, the 2019 Sustainable Development Report said Vietnam was up three ranks on the Sustainable Development Goal (SDG) Index this year. The report is prepared by the U.N.’s Sustainable Development Solutions Network and Germany-based foundation Bertelsmann Stiftung.

The country is ranked 54th among 162 countries and territories on the SDG Index, which tracks countries’ performances on achieving the 17 SDGs set by the United Nations General Assembly in 2015, including clean water, affordable energy, strong institutions and reduced inequalities.