‘More and Faster’: UN Calls to Shrink Buildings’ Carbon Footprint

 Snow capped mountains are seen behind the downtown Los Angeles skyline, California, US, March 7, 2025. (Reuters)
Snow capped mountains are seen behind the downtown Los Angeles skyline, California, US, March 7, 2025. (Reuters)
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‘More and Faster’: UN Calls to Shrink Buildings’ Carbon Footprint

 Snow capped mountains are seen behind the downtown Los Angeles skyline, California, US, March 7, 2025. (Reuters)
Snow capped mountains are seen behind the downtown Los Angeles skyline, California, US, March 7, 2025. (Reuters)

Countries must move rapidly to slash CO2 emissions from homes, offices, shops and other buildings -- a sector that accounts for a third of global greenhouse gas pollution, the United Nations said Monday.

Carbon dioxide emissions from the building sector rose around five percent in the last decade when they should have fallen 28 percent, according to a new report by the United Nations Environment Program (UNEP).

It said emissions had plateaued since 2023 as climate policies began to have an impact, particularly green building standards, the use of renewable energy and electrified heating and cooling.

But the building sector still consumes 32 percent of the world's energy and contributes 34 percent of CO2 emissions, the report found.

"The buildings where we work, shop and live account for a third of global emissions and a third of global waste," said Inger Andersen, Executive Director of UNEP.

"The good news is that government actions are working. But we must do more and do it faster."

She called on nations to include targets to "rapidly cut emissions from buildings and construction" in their climate plans.

The report said that while most of the countries that signed up to the 2015 Paris climate deal -- nearly 200 have signed -- mention the sector, so far only 19 countries have sufficiently detailed goals in their national carbon cutting plans.

The report said that as of 2023, important metrics like energy-related emissions and the adoption of renewable energy "remain well below required progress rates".

That means that countries, businesses and homeowners now need to dramatically pick up the pace to meet the 2030 emissions reduction targets.

- 'Critical challenge' -

Direct and indirect CO2 emissions will now need to fall more than 10 percent per year, more than double the originally envisaged pace.

The rollout of renewables is a similar story.

The share of renewables like solar and wind in final energy consumption rose by only 4.5 percentage points since 2015, well behind the goal of nearly 18 percentage points.

That now needs to accelerate by a factor of seven to meet this decade's goal of tripling renewable energy use worldwide, UNEP said.

The report urged countries to accelerate the roll-out of renewable technologies and increase the share of renewables in the final energy mix to 46 percent by 2030 -- a rise of around 18 percent.

It also called on policymakers to increase energy efficiency retrofits to include better design, insulation and the use of renewables and heat pumps.

More work also needs to be done to improve the sustainability of materials like steel and cement, whose manufacture accounts for nearly a fifth of all emissions from the building sector.

But the report did say that circular construction practices were increasing in some areas, with recycled materials accounting for 18 percent of construction inputs in Europe.

The authors urged all major greenhouse gas emitters to take action by introducing zero-carbon building energy codes by 2028, and called on other countries to create and tighten their regulations within the next 10 years.

The report highlighted positive national policies from China, France, Germany, Mexico and South Africa among others.

But it said financing remained a "critical challenge".

In 2023, it found that global investment in energy efficiency in buildings fell seven percent from a year earlier to $270 billion, driven by higher borrowing costs and the winding back of government support programs, notably in Europe.

Those investments now need to double -- to $522 billion -- by 2030, it said.



Quite Dramatic End to a Planet Swallowed by its Host Star

An artist's concept shows a ring of hot gas left after a star consumed a planet, in this undated illustration. NASA, ESA, CSA, Ralf Crawford (STScI)/Handout via REUTERS
An artist's concept shows a ring of hot gas left after a star consumed a planet, in this undated illustration. NASA, ESA, CSA, Ralf Crawford (STScI)/Handout via REUTERS
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Quite Dramatic End to a Planet Swallowed by its Host Star

An artist's concept shows a ring of hot gas left after a star consumed a planet, in this undated illustration. NASA, ESA, CSA, Ralf Crawford (STScI)/Handout via REUTERS
An artist's concept shows a ring of hot gas left after a star consumed a planet, in this undated illustration. NASA, ESA, CSA, Ralf Crawford (STScI)/Handout via REUTERS

In May 2020, astronomers for the first time observed a planet getting swallowed by its host star. Based on the data at the time, they believed the planet met its doom as the star puffed up late in its lifespan, becoming what is called a red giant.

New observations by the James Webb Space Telescope - sort of a postmortem examination - indicate that the planet's demise happened differently than initially thought, according to Reuters.

Instead of the star coming to the planet, it appears the planet came to the star, with disastrous consequences – a death plunge after an erosion of this alien world's orbit over time, researchers said.

The end was quite dramatic, as evidenced by the aftermath documented by Webb.

Reuters wrote that the orbiting telescope, which was launched in 2021 and became operational in 2022, observed hot gas likely forming a ring around the star following the event and an expanding cloud of cooler dust enveloping the scene.

“We do know that there is a good amount of material from the star that gets expelled as the planet goes through its death plunge. The after-the-fact evidence is this dusty leftover material that was ejected from the host star,” said astronomer Ryan Lau of the US National Science Foundation's NOIRLab, lead author of the study published in the Astrophysical Journal.

The star is located in our Milky Way galaxy about 12,000 light-years from Earth in the direction of the constellation Aquila.

A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The star is slightly redder and less luminous than our sun and about 70% of its mass.

The planet is believed to have been from a class called “hot Jupiter’s” - gas giants at high temperatures owing to a tight orbit around their host star.

“We believe it probably had to be a giant planet, at least a few times the mass of Jupiter, to cause as dramatic of a disturbance to the star as what we are seeing,” said study co-author Morgan MacLeod, a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics.

Jupiter is our solar system's largest planet.

The researchers believe that the planet's orbit had gradually deteriorated due to its gravitational interaction with the star, and hypothesized about what happened next.

“Then it starts grazing through the atmosphere of the star. At that point, the headwind of smashing through the stellar atmosphere takes over and the planet falls increasingly rapidly into the star,” MacLeod said.

“The planet both falls inward and gets stripped of its gaseous outer layers as it plows deeper into the star. Along the way, that smashing heats up and expels stellar gas, which gives rise to the light we see and the gas, dust and molecules that now surround the star,” MacLeod said.

But they cannot be certain of the actual fatal events.

“In this case, we saw how the plunge of the planet affected the star, but we don't truly know for certain what happened to the planet. In astronomy there are lots of things way too big and way too 'out there' to do experiments on. We can't go to the lab and smash a star and planet together - that would be diabolical. But we can try to reconstruct what happened in computer models,” MacLeod said.

None of our solar system's planets are close enough to the sun for their orbits to decay, as happened here. That does not mean that the sun will not eventually swallow any of them.

About five billion years from now, the sun is expected to expand outward in its red giant phase and could well engulf the innermost planets Mercury and Venus, and maybe even Earth. During this phase, a star blows off its outer layers, leaving just a core behind - a stellar remnant called a white dwarf.

Webb's new observations are giving clues about the planetary endgame.

“Our observations hint that maybe planets are more likely to meet their final fates by slowly spiraling in towards their host star instead of the star turning into a red giant to swallow them up. Our solar system seems to be relatively stable though, so we only have to worry about the sun becoming a red giant and swallowing us up,” Lau said.