Two major science-oriented marches are slated to take place in Washington, D.C., in the span of a week, starting Saturday. But despite the fact that it will be difficult for most people to book tickets to stay in D.C. on two consecutive weekends, organizers insist that the two events — which they say promote different, but related, goals — will complement one another, rather than compete for support.

The March for Science is scheduled for Saturday, coinciding with Earth Day. And the People’s Climate March will occur just a week later on April 29, which marks the 100th day of Donald Trump’s presidency. In the intervening week, a number of events and demonstrations have also been planned by organizers of the climate march.

Both events are expected to draw large crowds of attendees journeying in from outside the D.C. area, just as the Women’s March did in January. And given that supporters of science are generally likely to care about (or at least believe in) climate change, and vice versa, the proximity in time of the two marches raises the question of whether they might inadvertently end up competing with one another.

In fact, climate march organizers are urging participants who are interested in both events, but unable to make it to Washington for both, to attend satellite science marches in their home cities and then journey to the capital for the main climate march — a request that may reflect concerns about how attendance would be affected otherwise.

Organizers of both marches at one point discussed combining the two events, said Paul Getsos, national coordinator for the Peoples Climate Movement, the coalition organizing the climate march. But ultimately, the two events espouse slightly different, although complementary, goals, he said.

The People’s Climate March is one event in a broader political movement that extends beyond the issue of basic climate science, according to Getsos. The movement reflects the idea, touted by many environmental and social justice groups, that climate change is as much a social issue as a scientific one.

“We are a broad-based coalition that represents immigrants and workers and women and people of color and multi-issue community organizations,” he said.

According to Getsos, this year’s climate march was planned and scheduled for April 29 before the presidential election took place last year, and was deliberately set for the 100th day of the new administration, regardless of the election’s outcome. That said, he added, the Trump administration’s dismissive attitude toward climate change, and its efforts to roll back multiple Obama-era environmental regulations, have added fuel to the movement’s urgency.

The March for Science, on the other hand, was organized post-inauguration, largely as a reaction to concerns about the Trump administration’s treatment of scientific research and science-related issues, including the issue of climate change. That said, organizers have touted the march as a nonpartisan — although still inherently political — event that “call[s] for science that upholds the common good and for political leaders and policymakers to enact evidence based policies in the public interest.”

March for Science organizers referred a request for comment about whether their event could compete with the Climate March to the League of Conservation Voters, which was participating in both events.

“I think they’re absolutely a complement,” said Jennifer Allen, senior vice president of communities and civic engagement at the League, a political and environmental advocacy group. The organization is a sponsor of the Peoples Climate Movement, as well as a participant in the March for Science — although most of the organization’s attendees will likely be participating in a sister march taking place in Philadelphia on Saturday, Allen noted.

“The Science March is about respecting science, the Peoples Climate March is about acting on it,” added Ploy Achakulwisut, a PhD candidate in atmospheric science at Harvard University, in a statement included in a recent release from environmental advocacy group reaffirming that the two events are “inherently connected.”

In fact, sister events for both the climate and science marches have been organized in cities all over the country, a tactic which may help address some of the attendance issues that are likely still inevitable as a result of the two events’ proximity. Participants who can only make it to Washington for one event or the other could have the option of attending the second march in a city a little closer to home.

However, it’s hard to shake concerns about competition. For its part, the Peoples Climate Movement is encouraging everyone who’s able to come to the main march in D.C., and to attend local March for Science events in their home cities if there’s a conflict for people interested in participating in both.

An FAQ on the climate march website suggests that “Unless you live in Washington, D.C. and can easily attend both, we encourage you to take part in a local March for Science on April 22 and then come to D.C. for the Peoples Climate March on April 29th.”

“Our position is if you march for science in your communities on April 22, we hope that you will come to Washington, D.C. to show the Trump administration that there is a strong resistance at the end of 100 days,” Getsos said.