Japan has made climate change awareness the overarching theme of this year's meeting of rich nations and reminders to be environmentally aware are everywhere, down to the summit logo depicting a sprouting plant.

Environment-related booths dominate the entrance to the international media centre, including a bank of computer screens headlined "Let's carbon offset!"

With a few keystrokes, you can calculate your emissions from attending this week's summit in northern Japan, then choose a project to contribute to in order to stay "carbon neutral".

A reporter coming from Singapore, flying from Tokyo to Hokkaido and staying in a hotel for five nights, for example, needs to offset 2.72 tonnes of carbon dioxide equivalent.

A little more than $250 of investment in a forestation project in Hokkaido will pay for three carbon offsets, in this case three trees that will reduce three tonnes of CO2 equivalent in 30 years.

"Not so many" people have stopped by to erase their carbon footprint, admitted Ai Kimura of KPMG AZSA Sustainability, which is running the project on the Japanese government's behalf.

She said Japan plans to offset the entire summit once all the emissions are calculated, with preliminary estimates at around 25,000 tonnes of CO2.

US President George W. Bush, who was initially skeptical of the link between human activity and global warming, arrived in Hokkaido on Sunday.

White House staff gathered in the conference room on Air Force One just before arrival to celebrate his birthday Bush turned 62 on Sunday with a coconut cake carrying one candle.

"We all said 'surprise' and he dutifully pretended to be surprised," White House spokeswoman Dana Perino said.

Senior staff gave Bush a wooden box made from a scarlet oak that fell on White House grounds in October 2007, Perino said.

With as many as 22 world leaders due to attend different days of this year's G8, security has been no joke and 21,000 police have been deployed in Hokkaido alone.

But even security guards got into the spirit at the press centre, riding around the sprawling complex on two-wheel scooter Segways.

"We are using this because it's environmentally friendly," said security man Mitsugu Kubo, though how a scooter could be better for the environment than two feet was not so clear.

The true reason may well have been more pedestrian.

"Usually, we have to walk, so we get tired, but we don't get tired with this," said Kubo, an employee of Rising Sun Security Service.

A fleet of electric plug-ins, hybrids and hydrogen fuel cell cars await those attending the summit for use or test drives, supplied by Japan's top seven car makers.

Many fuel cell cars are still prototypes available only for lease, but commercial sales of some other summit autos, like Mitsubishi Motors' pure electric i-MiEV or Subaru's plug-in Stella, are coming as soon as 2009.

Honda FCX Clarity sedans are ferrying summit delegates after the hydrogen fuel cell sedan's debut this week ahead of a program to lease a fleet of the cars in the United States starting this month, mainly in California.

But the water-emitting cars face the reality of only about 60 US hydrogen stations, compared with about 180,000 gas stands.

Even in Toyako, the closest hydrogen stand is about 20 km (13 miles) away, due to safety concerns.

Japanese toilet technology is always a marvel to the uninitiated, with its rows of incomprehensible buttons and artificial flushing sounds and heated seats.

But even by local standards, the Toyako summit toilets ("designed exclusively for this site") are special and sure to give you a start when they pop open at the wave of a hand.

Aside from its futuristic look, this "hybird ecology system" promises water savings of up to 31 percent compared to a conventional toilet, employing a combination of "tornado" and "jet" flushing systems.

Just watch out for that bidet but that's another story.