It is hard to believe that as I left for graduate school, one of my aunts bitterly complained, “Why do you need all this education, your parents are wasting their money, and what boy will ever want to marry you, a girl taking science, really!”On the other hand, my grandmother, who had a grade-eight education and was a widow at age 23 with two children, understood what the opportunity meant, and hugged me, “You will be the second one to go to university in our family, my daughter and my granddaughter.”November 10th marks “World Science Day for Peace and Development”, a day to renew Canada's commitment to restoring science to benefit our society, to draw attention to the challenges faced by science and scientists, and to raise support for scientific exploration.On this day, I think of my grandmother and the scientists who work for a better tomorrow. Science matters more than ever before because the challenges we face are greater -- climate change, emerging and re-emerging diseases -- and the potential benefits are profound.Canada therefore needs robust science for the public good: for example, to identify risks to ecosystems and human health; and to protect the health and safety of Canadians and the communities in which we live.Unfortunately, science remains under persistent attack in Canada, despite the fact that the benefits of university research and development are $15 billion, and 150,000 to 200,000 person-years of employment per year.Specific instances of the government's war on science include: cutting $148 million from the federal granting councils in 2009; cutting funding to the Experimental Lakes Area and the Polar Environmental Atmospheric Research Lab; and putting in place new media protocols to prevent researchers from discussing their peer-reviewed research.Quite simply, there is no coherent science policy, and no comprehensive research and development policy. Meanwhile other countries are investing in science at a much higher rate, and focusing their investments on strong performers.But we can imagine a different future: a government that will bridge the gap between science and society; will use data for decision-making — and not eliminate a major source of evidence, the long-form census; and will ensure that women are better represented in science, technology, engineering, and math (STEM) fields.If Canada is to succeed in the knowledge economy and out-compete the rest of the world, we need to utilize all our talent, regardless of gender. We need to know what challenges women face entering STEM programs, and what holds them back from completing their studies and working in their chosen fields.We also need to recognize that if women are already facing barriers to entering science, it does not help if the national climate is perceived to be less than supportive owing to weak leadership from Ottawa.Biases and challenges do persist, especially for women in STEM fields. After all, it is not too long ago that a Harvard University President remarked that intrinsic aptitude could possibly explain the gender gap at the higher levels of research in math and science.Today young men make up less than 45 percent of university entrants in many institutions. And while the gender gap is smaller for the biological sciences and reversed for medical programs, Canada needs more women computer scientists, engineers, mathematicians, and physicists.Canada remains in the bottom third of OECD countries for Masters and doctoral degrees; and in order to increase the output of highly qualified graduates, we must increase the number of women in STEM programs.Over the past two decades, I have been pleased to see “penthouse pin-ups” disappear from offices, to witness “top” women graduates get the top spots at graduate school, and to no longer hear professors say they would never take “girls” to do field work “because they just can't keep up”.One of the most egregious experiences I heard on a Canadian campus was that of a male colleague who began each year by asking the young women in his first-year class to stand and take a deep breath; the students dutifully obliged, thinking new science was about to be revealed. Instead, the professor merely said, “Thank you”.Although women make up a bit more than half of the world's population, men still hold the lion's share of jobs in STEM fields and take home most of the prestigious science awards. In the United States, women receive half the doctorates in science and engineering, yet account for only 21 percent of full science professors and a paltry 5 percent of full engineering professors.What gains have Canadian women made in STEM fields, what are the remaining areas of underrepresentation, and what is their earning potential versus their non-STEM colleagues?All governments should inspire girls and young women to broaden their job aspirations before they start their careers, through partnerships with education and science. Could the government implement a STEM diversity programme, and might government scientists develop partnerships with children's organizations so that they could develop hands-on experience in science, and be inspired to think about STEM fields?What talented women scientists could the government appoint to serve as role models for women and girls? What steps could the government take to increase the number of graduates — and particularly, women graduates -- with advanced credentials in STEM fields to enhance our country's innovation and productivity? What educational opportunities, funds, and supports could the government make available to address barriers to women and girls? And what action could the government take to ensure better conditions in the STEM workforce?I loved my former life as a scientist and continue to mentor numerous young women. I hope that they face fewer of the challenges I faced — from the blatant sexism of being grossly underpaid to the subtle sexism of backs gently turned to prevent one from joining a discussion — and hope their daughters will face none of these challenges, but only new and ever-expanding opportunities in our great country.Kirsty Duncan, M.P., is the Liberal party critic for CIDA, consular affairs, and status of women.