I am a Bernie Sanders supporter, but I have tried very hard not to criticize Hillary Clinton during this primary campaign. If she wins the nomination, she will need my support, and if she doesn't, Bernie will need hers.

I have been defending Clinton as the only possible vote against a Republican if she gets the nomination, largely because any of the Republicans would pull the United States out of the Paris climate agreement and send us headlong into the unmitigated disaster of a destabilized climate.

I, like 92.2 percent of those in Climate Hawks Vote who voted to endorse Bernie Sanders, believe that his climate plan is stronger on climate than Hillary’s. But Hillary has promised an expansion of renewable energy large enough to power every home, and continuation of the Clean Power Plan that undergirds the U.S. pledge to the Paris Agreement.

When the question has arisen in Bernie circles of who we should vote for if Bernie doesn't get the nomination, some people have argued for the "long game" of voting their conscience for Green Party candidate Jill Stein or writing in Bernie.

The thinking is that even if this results in a Republican being elected, that will motivate progressives to come together in 2020 like never before, and that 2020 is a more important year to elect a progressive Democrat since that is a census year that will determine how Congressional and state legislative lines are drawn. This school of thought argues that even if Hillary is elected, she will likely be a one-term president because it’s extremely rare for the same party to hold power for so long.

In these debates, I have argued the other side. My position has been that we should vote for Hillary because we cannot afford four years of a Republican who will roll back all progress on climate. If a Republican pulls us out of the Paris Agreement, as Cruz has promised, or dismantles the EPA which oversees the Clean Power Plan, as Trump has promised, then the planet is officially screwed.

Climate change is the only issue on a non-negotiable timeline. Physics doesn't wait for politics, and we are out of time to start taking serious action on climate. Perhaps Hillary would not ban fossil fuel lobbyists from the White House as Bernie would. She would not support a ban on fracking as Bernie would. She might not fight for a carbon tax as Bernie would.

But she also would not send us headlong into planetary destruction by pulling us out of the Paris Agreement, and she would make progress on jump-starting renewables. Even if she did approve more pipelines and fracking, we would at least tread water on addressing climate change, and we could gain some time to do more. Or so my argument has gone.

Viral video

Unfortunately, this past weekend, Hillary has made it much harder for me to continue defending her as a climate candidate. Unless you have been hiding under a rock for the past three days, you have seen the video of Hillary losing her temper after a campaign event Friday night when Eva Resnick-Day, an activist from Greenpeace, asked if she would reject fossil fuel money in her campaign.

"I do not have -- I have money from people who work for fossil fuel companies," Clinton said, jabbing her finger at Resnick-Day. "I'm so sick. I'm so sick of the Sanders' campaign lying about me. I'm sick of it."

What's worse, rather than simply apologizing for her rudeness to Resnick-Day -- who could not have been more polite and even started by thanking Hillary for tackling climate change -- Hillary has doubled down on her claims that this was all lies from the Sanders campaign.

She continued in speeches on Saturday to assert that the Sanders campaign was lying about her campaign contributions from fossil fuels, and on Sunday did an interview on Meet the Press with Chuck Todd in which she again claimed "it's just not true," then went on to say:

"I feel sorry sometimes for the young people who, you know, believe this. They don't do their own research."

There are so many things to say about this that it's hard to know where to start. Above all, it is a complete insult to millennials, who are the most politically involved generation since the baby boomers of the 60s, and who know how to dig up any information they might want on the internet. It's also an insult to us older voters who support Bernie, because we too have done our research.

There are so many ways that Hillary's claims in this interview are wrong. First, Resnick-Day, who asked the question of Hillary, is not with the Sanders campaign. She is with Greenpeace. The two are not the same thing. Sanders has been quoting Greenpeace research when discussing fossil fuel donations to Hillary's campaign, but Greenpeace did not do the research for Bernie.

Greenpeace did the research as a climate activist organization devoted to pushing all the presidential candidates on climate issues. Further, Greenpeace did not solely target Hillary with this campaign. They, along with 20 other environmental organizations in the Fix Democracy campaign, have been bird-dogging all the presidential candidates for months with climate questions.

I personally received training about how to bird dog candidates on climate issues at the Ohio Sierra Club retreat in January, where Yong Jung Cho from 350 Action showed videos of questions to Ted Cruz, Marco Rubio, and Clinton. She explained how the bird-dogging process puts the candidates' positions on record, and how it sometimes leads candidates to change their positions.

Asking questions of candidates is an integral part of the democratic process, and every candidate should be prepared to answer questions about their positions on the issues at campaign events. That's what makes Hillary's blowup at Resnick-Day so mystifying. I personally was shocked when I first saw the footage. I've never seen Hillary act like this. Perhaps the long campaign is wearing on her, and if so, that is understandable. But that requires an apology for losing her temper, not doubling down on the claim that this is all lies from the Sanders camp.

Doing the research

That also brings up the question, is what Greenpeace said all lies? How true are the claims from their research? Clinton's spokesman, Nick Merrill, said the candidate "has not taken a dollar from oil and gas industry PACs or corporations." It's good she has not because federal election law makes it illegal for candidates to accept money directly from corporations.

However, neither Greenpeace nor Sanders has claimed this is what she did. Greenpeace lays out its claims about Clinton's connections to the oil and gas industry clearly and thoroughly, backing each one up with links and citations. They are:

• Clinton's campaign committee received $309,107 in direct contributions from people working for fossil fuel companies
• Clinton's campaign committee received $1,465,610 in bundled and direct donations from lobbyists currently registered as lobbying for the fossil fuel industry.
• Clinton's SuperPAC Priorities Action USA received $3,250,000 in donations from large donors connected to the fossil fuel industry.

Let's look at each of these claims a little more closely.

Direct contributions: $309,107

This is sourced to the Center for Responsive Politics, which runs a website called Open Secrets, where anyone can look up contributions to political candidates. A look at oil and gas contributions during the 2016 presidential campaign shows the amount each candidate has gotten. Clinton comes in fourth after Cruz ($1,013,249), Bush ($498,202), and Rubio ($356,389). Sanders got $53,760 and Martin O'Malley got $9,450. These are contributions not from fossil fuel corporations themselves, but from individual employees. That could be anyone from a secretary to the CEO.

The Fix Democracy pledge that Greenpeace and others have been asking candidates to sign is as follows:

I pledge allegiance to a democracy of, by, and for the people.

If elected, I pledge to fight for a people-powered democracy where every voice is heard

By defending the right to vote for all, and

Supporting common-sense measures like public funding for campaigns and overturning Citizens United to ensure a government by and for the people, not the biggest donors.

And I will prove that I work for the people by refusing money from fossil fuel interests and by championing these solutions for a people powered democracy on the campaign trail.

Sanders signed the pledge on the first day it was out, and O'Malley signed it shortly after. Clinton has not signed it. O'Malley has since dropped out of the race. Greenpeace said this weekend that they are checking into whether any of the $53,760 Sanders took in direct contributions was after he signed the pledge. So far they have found no evidence of that.

Bundled and direct donations from lobbyists: $1,465,610

This is the area of more concern. Individual lobbyists from all industries have donated more money to the Clinton campaign ($919,477) than to any other candidate except Jeb Bush ($1,637,294), who is now out of the race. 58 lobbyists from oil, coal and gas companies have personally given $138,400 to the Clinton campaign. Of those 58, 11 are bundlers, meaning they combined their own donations with donations collected from others, for total bundled contributions of $1,327,210.

Some of these lobbyists do business with some questionable entities. Examples from investigative journalists Paul Blumenthal and Kate Sheppard include:

Scott Parven and Brian Pomper, lobbyists at Akin Gump Strauss Hauer & Feld, have been registered to lobby for the Southern California-based oil giant Chevron since 2006, with contracts totaling more than $3 million. The two bundled Clinton contributions of $24,700 and $29,700, respectively. They ... were part of a much-criticized campaign by Chevron to manipulate Congress into inserting language into the Andean Trade Preferences Act that would require Ecuador to dismiss a longstanding lawsuit against the company for polluting the Amazon jungle.

Ankit Desai, vice president for government relations at top LNG exporter Cheniere Energy, bundled $82,000 to the Clinton camp, with much of it coming from Cheniere Energy executives. The company won the first approval to export gas to countries outside of U.S. free-trade agreements. The company is seeking approval to open additional terminals to export LNG, and will likely need a friend in the White House come 2017.

Bundler Gordon Giffin is a former lobbyist for TransCanada, the company working to build the controversial Keystone XL pipeline. Giffin sits on the board of Canadian Imperial Bank of Commerce, an investor in the pipeline. The Canadian bank paid Clinton $990,000 for speeches in the months leading up to her presidential announcement.

While some people see bringing up lobbyist donations as impugning a politician's integrity, these contributions are a matter of public record. Greenpeace cites the Lobbying Disclosure Act database, while Blumenthal and Sheppard cite filings by the Clinton campaign with the Federal Election Commission. If it is considered unspeakable to bring up a candidate's donations from a certain industry’s lobbyists, perhaps the candidate should not be taking them in the first place.

However, what the Clinton campaign says is a personal attack in 2016 did not seem to be such in 2008, when Clinton released an ad saying the same thing about her then-opponent. "Barack Obama accepted $200,000 from executives and employees of oil companies," the ad said. "Obama voted for the Bush-Cheney energy bill that puts $6 billion in the pocket of big oil. Hillary voted against it. She will make oil companies pay to create the new jobs in clean energy America needs."

Donations to Clinton SuperPAC Priorities USA: $3,250,000

Donations to SuperPACs are where truly huge amounts of money can flow into a campaign. Legalized under Citizens United, SuperPACs allow individuals and corporations to make unlimited contributions to election campaigns, so long as the SuperPAC does not coordinate directly with the official campaign.

Here Hillary’s SuperPAC Priorities USA got $3.25 million -- but that amount is dwarfed by fossil fuel donations to SuperPACs for Bush ($30.6 million), Cruz ($25.6 million), Rubio ($7.7 million), Perry ($6.7 million), and Christie ($5.6 million). Sanders has no SuperPAC, and Trump is funding his own campaign. Greenpeace cites Center for Responsive Politics for this data.

Although legally candidates are not allowed to coordinate directly with SuperPACs, many observers say it is very hard to completely draw these lines. Clinton personally raised money for Priorities USA. She also does coordinate directly with another SuperPAC, Correct the Record, managed by operative David Brock, by exploiting a loophole in the law to keep all communications online.

All told, according to Greenpeace research, the Clinton campaign has taken $4.5 million in fossil fuel contributions. To be sure this is not as much as many of the Republicans have taken, especially Cruz, but it's not chump change either. And it's hard to see where any of this information, documented in public records, is a lie.

In addition, neither Greenpeace nor Sanders has brought up another source of fossil fuel donations: contributions to the Clinton Foundation. These contributions are not to the campaign, which is why Greenpeace left them out. But they are quite large, including, as FAIR pointed out, "at least $10 million from Saudi Arabia; at least $5 million from Kuwait, as well as from oil-refining billionaire Mohammed H. Al-Amoudi; at least $1 million from ExxonMobil, natural gas-producer Cheniere Energy, Qatar, Oman, United Arab Emirates, the Dubai Foundation, Friends of Saudi Arabia, etc."

Although neither Greenpeace nor Sanders consider the donations to the Clinton Foundation to be fair game, Republicans certainly do. They have already done opposition research on this point, and will continue to push it if Hillary gets the nomination. When that happens, she needs to have a better answer than "it's all lies," because the information is right there on the Foundation website.

Fact checks?

Several "fact checks" in mainstream media came out in the days following release of the video showing Clinton losing her temper with Greenpeace activist Resnick-Day. Clinton cited these articles as "debunking" claims from Sanders in the interview on Meet the Press. But do they actually show Greenpeace's research to be false?

NPR’s fact check considered only the first of Greenpeace's three types of donations from fossil fuel interests, direct donations from employees, which it dismissed as "two-tenths of 1 percent of Clinton's $159.9 million overall fundraising." NPR did not consider lobbyist donations or donations to SuperPACs. This led Fairness and Accuracy in Media to criticize NPR as trying to blunt the effect of the Greenpeace research.

The New York Times fact check did consider all three parts of fossil fuel funding for the Clinton campaign, but dismissed them as "not that much" because they are a "small slice" of her overall fundraising. This begs the question: If fossil fuel funding is so unimportant to the Clinton campaign, why not just take the pledge to forgo it? Had Clinton done that to begin with, Greenpeace activists would not be asking her questions about it, and Sanders could no longer use it as a talking point.

If fossil fuel funding is so unimportant to the Clinton campaign, why not just take the pledge to forgo it?

Neither NPR nor The New York Times say Greenpeace or Sanders are lying, but the Washington Post practically does. The "Sanders campaign has its own math, which is borrowed from a Greenpeace analysis," its article says. In particular, the Post thinks Greenpeace should not have counted bundled donations from fossil fuel lobbyists, since lobbyist shops work for other clients.

Greenpeace outlines its calculations of lobbyist donations in detail. Nine of the 58 lobbyists are in-house employees of fossil fuel corporations, and two of those are bundlers. For example, Ankit Desai, vice president for government relations at top LNG exporter Cheniere Energy, bundled $82,000, with much of it coming from Cheniere Energy executives.

45 were freelance lobbyists hired by fossil fuel corporations. 43 gave the maximum of $2,700 each themselves, and nine were bundlers giving the max themselves plus donations from others. In addition were four coal industry lobbyists, three of whom gave the $2,700 maximum.

Fossil fuel taint

Why is it a problem for people who lobby for the fossil fuel industry to raise money for presidential candidates? The answer is that fossil fuel use is directly threatening the stability of the worldwide climate, yet the federal government is deeply enmeshed in fossil fuel extraction.

Recently activists shut down an auction by the Bureau of Ocean Energy Management of oil and gas drilling rights on 43 million acres in the Gulf of Mexico. Why is the federal government auctioning off new leases for fossil fuel extraction when we know that 80 percent of known fossil fuel reserves must stay in the ground if we hope to have a liveable planet?

Despite that fact, fossil fuel corporations are subsidized worldwide to the tune of $10 million every minute, according to the International Monetary Fund. The United States subsidizes fossil fuel corporations $34.2 billion a year through tax breaks, direct support, and low-cost leases on public lands and oceans, according to a report by Oil Change International.

Although the United States along with other G20 nations pledged to phase out fossil fuel subsidies in 2009, these subsidies have actually increased 35 percent since President Obama took office, the report said. Among the most direct beneficiaries are ExxonMobil and Marathon Petroleum, both represented by lobbyists donating to Clinton's campaign.

Are such donations done for a quid pro quo? That is not likely, and in any case it would be almost impossible to prove. But that is not the point. In a campaign finance system in which money equals speech, corporations that can hire lobbyists have a lot more access to officeholders than do regular citizens in whose interest it is to have a livable planet.

Candidates who take money from an industry whose activities are literally destabilizing the climate, and that has worked for decades to spread misinformation about the science of climate change, are giving those industries a place at the policy-making table. The fossil fuel industry deserves no such legitimacy. No politician should take donations from an industry that is systematically and knowingly engaging in mass death and extinction on a global scale.

Leave it in the ground

There is a solution to this issue, of course: Get the government out of the business of fossil fuel extraction. That is a key plank in the Sanders climate plan, and Sanders with several other senators has introduced the Keep It In the Ground Act, which would block corporations from pursuing leases for coal, oil, gas, shale, and tar sands extraction on federal land, as well as ban offshore drilling in the Arctic and Atlantic Oceans and halt leases in the Pacific and Gulf of Mexico.

In the end, I do not believe either Greenpeace or Sanders are lying about the fossil fuel contributions to Clinton's campaign. Whether those donations will influence her is another question, but corporations would not make them if they did not hope for some type of influence or at least access to the candidate that the rest of us do not have.

More important, Clinton could end all such speculation right now by simply rejecting fossil fuel donations, as Sanders and O'Malley did early on. If these donations are such a small part of her overall funding, she wouldn't miss them, and the dividends in good publicity she would reap would be well worth cost of giving this money up.

If Clinton rejected fossil fuel funding, it would be much easier for Bernie supporters such as myself to defend a vote for her in the general election to other climate-conscious Bernie supporters. Fossil fuel money is tainted, and as long as she takes it, she will be tainted in the eyes of many climate-conscious voters as well.