Described as one of the greatest Japanese geochemists and hailed as an "iron scientist", Katsuko Saruhashi would have been 98 years old on March 22.

In her honour, Google is changing its logo in 15 countries to an illustration of her.

But in her lifetime, she was not always recognised for her achievements and discrimination was an everyday affair.

This is her story:

World War II experience

Saruhashi was born in Tokyo in 1920 to Kuniharu and Kuno Saruhashi . As a child, she was often described as a shy and introverted little girl.

. As a child, she was often described as a shy and introverted little girl. A young Saruhashi sat in primary school watching raindrops slide down a window and wondered what made it rain.

Saruhashi had a passion for education that was also supported by her mother after their shared experience of the Second World War. She was convinced that women needed to acquire technical knowledge to gain independence.

She attended Toho University (then known as the Imperial Women's College of Science) and graduated in 1943.





First doctorate

While studying, Saruhashi met someone who would become her future mentor. Miyake Yasuo offered her a position at the Meteorological Research Institute.

During her time there she had the opportunity to study the CO2 levels in seawater.

"Now everyone is concerned about carbon dioxide, but at the time nobody was," she said, when she started she had to design her own techniques for measuring the gas.

She showed that the Pacific Oceans releases about twice as much carbon dioxide back into the atmosphere as it absorbs, meaning it could not help combat climate change.

For her work, she became the first woman to be awarded a doctorate in chemistry from the University of Tokyo in 1957.

Nuclear bombs

Saruhashi and her team were also recognised for being part of the first group in the world to look into the effects of bombs tested by the US and the Soviet Union in the world's atmosphere.

She discovered that radioactivity reached the coast of Japan. She was one the firsts to research on the issues of nuclear testing; her evidence was later used to stop those governments from performing nuclear tests.

Despite her pioneering work, Saruhashi is almost never cited in Western debates on climate change or the dangers of radiation testing.

She died on September 29, 2007, at the age of 87.

Recognition

Saruhashi was the first woman to be awarded a doctoral degree in chemistry from the University of Tokyo in 1957.

She was the first woman to be elected as the member of the Science Council of Japan, the country’s parliament of science in 1980.

She was the first woman to receive the Miyake Prize for geochemistry in 1985, and she established her own prize as well known as the Suruhashi prize which recognises female scientists who act as mentors and role models for younger female scientists.

"I wanted to highlight the capabilities of women scientists. Until now, those capabilities have been secret, under the surface," she was quoted saying.

In 1993, she won the Tanaka Prize from the Society of Sea Water Sciences.