• The central bank played a key role in brokering the rescue of embattled lender Credit Suisse over the course of a chaotic weekend in March.
• Thomas Jordan, chairman of the governing board at the SNB, said banking regulation and supervision will have to be reviewed in light of recent events.
• The demise of the country's second-largest bank fomented widespread discontent and severely damaged Switzerland's long-held reputation for financial stability.

The Swiss National Bank on Friday pledged to review banking regulations during its annual general meeting in Bern, following recent turmoil involving Credit Suisse.

Set against a backdrop of protest over its action on climate change and its role in the emergency sale of Credit Suisse to Swiss rival UBS, Thomas Jordan, chairman of the governing board at the SNB, said banking regulation and supervision will have to be reviewed in light of recent events.

"This will require in-depth analysis ... quick fixes must be avoided," he said, according to a statement.

The central bank played a key role in brokering the rescue of Credit Suisse over the course of a chaotic weekend in March, as a flight of deposits and plummeting share price took the 167-year-old institution to the brink of collapse.

The deal remains mired in controversy and legal challenges, particularly over the lack of investor input and the unconventional decision to wipe out 15 billion Swiss francs ($16.8 billion) of Credit Suisse AT1 bonds.

The demise of the country's second-largest bank fomented widespread discontent and severely damaged Switzerland's long-held reputation for financial stability. It also came against a febrile political backdrop, with federal elections coming up in October.

Jordan said Friday that future regulation will have to "compel banks to hold sufficient assets which they can pledge or transfer at any time without restriction, and which they can thus deliver as collateral to existing liquidity facilities." He added that this would mean his central bank could would be able to provide the necessary liquidity, in times of stress, without the need for emergency law.

The SNB faced questions and grievances from shareholders about the Credit Suisse situation on Friday, but the country's network of climate activists also sought to use the central bank's unwanted spotlight to challenge its investment policies. Activists failed to gain traction with a vote to reprimand the SNB's investment decisions, with just 0.8% of shareholders backing the move, according to Reuters.

Unlike many major central banks, the SNB operates publicly-traded company, with just over half of its roughly 25 million Swiss franc ($28.1 million) share capital held by public shareholders — including various Swiss cantons (states) and cantonal banks — while the remaining shares are held by private investors.

More than 170 climate activists have now purchased a SNB share, according to the SNB Coalition, a dedicated pressure group spun out of Alliance Climatique Suisse — an umbrella organization representing around 140 Swiss environmental campaign groups.

Around 50 of the activist shareholders were attendance on Friday, and activists had planned to make around a dozen speeches on stage at the AGM, climate campaigner Jonas Kampus told CNBC on Wednesday. Protests were also held outside the event with Reuters reporting that the campaigners totaled 100, leading to tight security.

The group is calling for the SNB to dispose of its stock holdings of "companies that cause serious environmental damage and/or violate fundamental human rights," pointing to the central bank's own investment guidelines.

In particular, campaigners have highlighted SNB holdings in Chevron, Shell, TotalEnergies, ExxonMobil, Repsol, Enbridge and Duke Energy.

Members of a Ugandan community objecting to TotalEnergies' East African Crude Oil Pipeline, were also set to attend on Friday, with one planning to speak on stage directly to the SNB directorate.

As well as a full exit from fossil fuel investments, activists are demanding that the SNB implement the "one for one rule," — a capital requirement designed to prevent banks and insurers benefiting from activities that are detrimental for the transition to net zero.

In this context, the SNB would be required to set aside one Swiss franc of its own funds to cover potential losses for each franc allocated to financing new fossil fuel exploration or extraction.

Ahead of the AGM, the central bank declined on legal grounds to schedule three motions tabled by the activists, and said on Wednesday that it would not comment on protest plans, instead directing CNBC to its formal agenda. Yet Kampus suggested that just the process of submitting the motions itself had helped expand public and political awareness of the issues.

"From all sides, there is public pressure and also political pressure that the SNB needs to change things. At this moment, the SNB is really far behind in terms of their actions taken compared to other central banks," Kampus told CNBC via telephone, adding that the SNB takes a "very conservative view" of its mandate regarding price stability and financial stability, which is "very narrow."

The shareholders' cause is also backed by a motion in parliament, with support from lawmakers ranging from the Green Party to the Centre [center-right party], which demands an extension of the SNB's mandate to cover climate and environmental risks.

"While other central banks around the world are going well beyond the steps taken by the SNB in ​​this respect — the SNB has repeatedly taken the position that its mandate does not give it sufficient leeway to take climate risks fully into account in its decisions and monetary policy instruments," reads the motion, filed on March 16 by Green Party lawmaker Delphine Klopfenstein Broggini.

"The present parliamentary initiative is intended to ensure this leeway and to make it clear that the SNB must take climate risks into account when conducting monetary policy."

The motion argues that climate risks are "classified worldwide as significant financial risks that can endanger financial and price stability," concluding that it is in "Switzerland's overall interest that the SNB proactively address these issues" as other central banks are seeking to do.

Kampus and his fellow activists hope the national focus on the SNB after the Credit Suisse crisis provides fertile ground to advance concerns about climate risk, which he said poses a risk to the financial system that is "several times larger" than the potential fallout from Credit Suisse's collapse.

"We feel that there is also a window of opportunity on the SNB side in that they maybe this time are a bit more humble, because they obviously also have done some things wrong in terms of the Credit Suisse crash," Kampus said.

He noted that the central bank has always asserted that climate risk was incorporated into its models and that there was "no need for further exchange with the public of further transparency."

"Very central to the SNB's work is that the public just needs to trust them. Trust is something that is very important to the central bank, and to demand trust from the public without leading up to it or supporting it with further evidence that we can trust them in the long run is quite scary, especially when we don't know what their climate model is," he said.

The SNB has long argued that its passive investment strategy, which invests in global indexes, is part of its mandate to remain market neutral, and that it is not for the central bank to engage in climate policy. Activists hope mounting political pressure will eventually force a change in legislation to broaden the SNB's mandate to accommodate climate and human rights as risks to financial and price stability.

UBS and Credit Suisse also faced protests from climate activists at their respective AGMs earlier this month over investment in fossil fuel companies.